Open The Big Bang is settled science. Whether there was an absolute first moment, and whether a beginning needs a cause beyond the universe, are open questions.
A Christian philosopher and an atheist physicist faced each other in a packed hall in New Orleans. It was February 2014, and they spent two hours on one question: does modern cosmology point to God? William Lane Craig said the universe began, so it needs a cause. Sean Carroll said physics does not work that way. Both were polite. Neither was persuaded.
Craig’s argument is not new. Muslim theologians sharpened it a thousand years ago, and it is still taught in sixth-form RE across Britain. The argument comes first, then the strongest replies, then what each tradition, and people without one, make of the question.
“He is the First and the Last, and the Outward and the Inward; and He is Knower of all things.”
Qur'an 57:3 · Pickthall (1930)
This verse, from the chapter al-Hadid (Iron), gives four of God’s Names together: al-Awwal, al-Akhir, az-Zahir and al-Batin. It says God is before everything, not that the universe began at a particular time. Centuries earlier, Isaiah had said it in his own words: “I am the first, and I am the last, and beside Me there is no God” (Isaiah 44:6, JPS 1917).
What science shows, and what it does not
Our science page on the beginning sets out the evidence for the Big Bang: space is expanding, the sky glows with leftover heat from an early hot, dense state, and the lightest elements exist in the amounts that state should have made. The European Space Agency’s Planck satellite puts the universe’s age at about 13.8 billion years.
Here is the part that matters for this question. The Big Bang model describes how the universe developed from that early state. It does not, on its own, tell us that there was a first moment of time. Near the very start, our two best theories, general relativity and quantum physics, give conflicting answers, and we do not yet have a theory that joins them.
In 2003 three physicists, Arvind Borde, Alan Guth and Alexander Vilenkin, showed mathematically that any universe that has, on average, been expanding cannot be extended forever into the past. Vilenkin told Tufts University in 2012 that this means inflation cannot go back forever. He also said, carefully, that he did not think it settles anything either way about God. Sean Carroll points out that the theorem applies to classical spacetime and says nothing about what quantum gravity might allow.
Other physicists propose models with no first moment. Stephen Hawking and James Hartle suggested in 1983 that the universe is finite in the past but has no edge, like the rounded bottom of a shuttlecock. Others propose bouncing or cyclic universes. In 2017 a team including Neil Turok argued the Hartle-Hawking idea fails mathematically; its defenders disagreed. None of these models is confirmed.
So the honest position in 2026: the universe’s history goes back 13.8 billion years to a hot, dense state, and whether that was an absolute beginning is unknown. Here science hands the question to philosophy.
The arguments, fairly
The kalam argument. Muslim theologians of kalam, such as al-Kindi in the ninth century and al-Ghazali in the eleventh, argued that an infinite series of past events could never have been completed, so the world must have begun. William Lane Craig revived the argument in 1979: whatever begins to exist has a cause; the universe began to exist; so the universe has a cause. That cause, he argues, must be beyond space and time, enormously powerful, and personal, because only a choice could start a timeless cause producing a first effect.
A Jewish voice in the same argument. In Baghdad in 933, Saadia Gaon opened The Book of Beliefs and Opinions with proofs that the world was created. One of them is the kalam’s core: an infinite past could never have been crossed to reach the present, so time must have begun.
Science has moved towards a beginning. For most of history, many philosophers assumed the universe was eternal. Craig and others argue that the Big Bang and the Borde-Guth-Vilenkin theorem make a beginning the best reading of the evidence, and that the old objection, ‘the universe has always been here’, is now harder to hold.
Even without a first moment. Ibn Sina and Thomas Aquinas did not need a beginning in time: anything that could have failed to exist depends on something else now, not only at the start. See our page on why there is something rather than nothing.
Causes may not apply. Sean Carroll argues that ‘everything that begins has a cause’ is a rule learned inside the universe, where there are time and laws. There is no reason to assume it applies to the universe as a whole. In physics, he says, what matters is whether a model fits the evidence.
The beginning may not be real. The ‘beginning’ may be a sign that our classical equations break down, not a real first moment. Eternal, bouncing and no-boundary models need no external cause. Vilenkin himself says his theorem does not prove anything about God, and his co-author Alan Guth has said the universe probably did not have a beginning, according to Carroll.
From a cause to God is a long step. Even if the universe had a cause, philosophers such as Graham Oppy argue, nothing shows that it is one, personal, good, or the God of any religion.
Where it stands
Open. The Big Bang is not in dispute. Whether there was an absolute first moment is unknown, and physicists disagree about it. Whether a beginning, if there was one, needs a cause outside the universe is a question of philosophy, and serious philosophers stand on both sides.
One more thing is worth knowing: some of the greatest religious thinkers held that reason alone cannot show the world began, and believed it by faith. The question is open inside the traditions too.
What each faith says
Judaism
“In the beginning God created the heaven and the earth.”
Genesis 1:1 · JPS 1917
The Torah opens with the most famous sentence in the Hebrew Bible: “In the beginning God created the heaven and the earth” (Genesis 1:1). Jewish tradition reads it as teaching that the world is made, not divine, and depends on its Maker. The thirteenth-century commentator Nachmanides (the Ramban) wrote that God first brought into being from absolute nothing a substance that was very small, ‘like a mustard seed’, from which everything else unfolded. Many readers find that image moving today; it is a reflection, not a scientific claim.
The great philosopher Maimonides, in his Guide for the Perplexed (around 1190), made a striking point. He said Aristotle had not demonstrated that the world was eternal, and nor could anyone demonstrate that it began. He accepted creation because the Torah teaches it, and said that if eternity were ever demonstrated, he would read Genesis differently.
Christianity
“In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made through him.”
John 1:1–3 · WEB
Christians share Genesis 1:1, and the Gospel of John begins with its own echo: “In the beginning was the Word” (John 1:1). Augustine of Hippo, around 417, wrote that the world was made not in time but with time: there was no ‘before’ in which God waited. Many physicists have noticed how close that is to the modern idea that time began with the universe.
Thomas Aquinas argued that reason cannot show the world had a beginning; Christians know it by revelation. When Pope Pius XII spoke in 1951 as if the Big Bang confirmed creation, Georges Lemaître, the Belgian priest and physicist who first proposed the theory, was uneasy. He thought science and faith should not be mixed in that way. Christian thinkers today are divided: some, like Craig, use the beginning as evidence; others, in Lemaître’s line, keep cosmology and creation apart.
Islam
“The Originator of the heavens and the earth! When He decreeth a thing, He saith unto it only: Be! and it is.”
Qur'an 2:117 · Pickthall (1930)
The Qur’an calls God the Originator, al-Badi’: “The Originator of the heavens and the earth! When He decreeth a thing, He saith unto it only: Be! and it is.” (2:117, Pickthall). The kalam argument grew inside Islam. Al-Ghazali, in The Incoherence of the Philosophers (around 1095), argued against philosophers who held the world was eternal. The Andalusian philosopher Ibn Rushd (Averroes) answered him with The Incoherence of the Incoherence. Both sides were sure they were defending God.
Modern Muslim scientists such as the astrophysicist Nidhal Guessoum accept the Big Bang and warn against claiming that the Qur’an foretold it. Many Muslims read verses like 21:30, on the heavens and earth once joined and then parted, with wonder; scholars differ on how far to link them with cosmology. What the Qur’an insists on is not a date but a relationship: everything that exists depends on God, who is the First.
Without religion
“Roughly speaking, the word humanist has come to mean someone who trusts to the scientific method when it comes to understanding how the universe works”
Humanists UK, ‘What is humanism?’ · original English
Non-religious people hold a range of views here. Many are content with the science: the Big Bang happened, and whether there was a first moment is for physicists to find out. Sean Carroll, who debated Craig in 2014, calls himself a naturalist and argues that the universe may need nothing outside itself. Agnostics say a question about what came ‘before’ time may have no answer we can reach, and that is no reason to invent one.
Some find the beginning the most moving fact of all. Carl Sagan, who preferred to call himself agnostic rather than atheist, spoke of human beings as a way for the cosmos to know itself. For many humanists the wonder needs no Creator. It is enough that matter made in the first minutes, and in the hearts of stars, now looks back and asks where it came from.
Same and different
Judaism, Christianity and Islam each teach that the universe depends on God and is not itself divine. Each has great thinkers, Maimonides, Aquinas and Ibn Rushd among them, who said reason alone cannot settle whether time had a beginning. The kalam argument passed between Muslim, Jewish and Christian thinkers in the Middle Ages. They differ in language: Christianity speaks of creation through the Word, Islam through God’s command ‘Be’, and Judaism through God’s speech in Genesis. Non-religious people share the wonder at the Big Bang; they differ on whether it needs anything beyond itself.
A moment to reflect
- If physicists showed tomorrow that the universe had no first moment, would that change what you believe? Why, or why not?
- Is ‘everything that begins has a cause’ something we know, or something we assume?
- Maimonides and Aquinas both said reason cannot prove the world began. Does that make faith weaker, or more honest?
- What would count as an explanation of the whole universe?
We end on a question
If the universe did begin, what kind of thing could begin it; and if it did not, does it explain itself?
Watch
A clear ten-minute introduction to cosmological arguments, including the kalam, and the main objections.
Alexander Vilenkin, co-author of the beginning theorem, explains what it shows and what it does not.
The full 2014 debate between William Lane Craig and Sean Carroll, the best single debate on this question.
The story of Georges Lemaître, the priest who proposed the Big Bang and kept it apart from apologetics.
Dr Khalil Andani explains Ibn Sina’s argument from contingency, which does not need a beginning in time.
Do it together
Split into pairs. One person argues the kalam argument for three minutes; the other replies using Carroll’s points. Then swap sides. Finish by asking: which argument was harder to make, and why?
Visit a planetarium, such as the one at the Royal Observatory Greenwich, or a free star party run by a local astronomy society. Afterwards, share one question it answered and one it left open.
Read aloud Genesis 1:1, John 1:1–3 and Qur’an 2:117. Ask each person what the verse says about God, and what it does not claim about science. Notice how much the three share.
Jewish tradition marks each new month with Kiddush Levanah, a blessing said outdoors under the waxing moon, praising the One who renews the months. On a clear night early in the lunar month, step outside, find the moon, and talk about what begins and what renews.
Listen together to the opening of Haydn’s oratorio The Creation (1798), written for Christian audiences, where the chorus bursts out on the words “and there was light”. Then look at an image of the cosmic microwave background, the oldest light we can see.
Go deeper
- Cosmological Argument (Stanford Encyclopedia of Philosophy) · article
- What happened before the Big Bang? Alexander Vilenkin (Tufts Now) · article
- Post-debate reflections, Sean Carroll (Preposterous Universe) · article
- Planck and the cosmic microwave background (ESA) · article
- Genesis 1 (Sefaria) · scripture
- Qur'an 57:1–6 (Quran.com) · scripture
- Saadya [Saadiah] Gaon (Stanford Encyclopedia of Philosophy) · article
- John 1 (Bible Gateway, WEB) · scripture
- What is humanism? (Humanists UK) · article
Check yourself
Three quick questions. No score, nothing saved.
1. Which part does the page call settled science?
2. Who debated this question in New Orleans in 2014?
3. Qur'an 57:3 calls God the First and the Last, and…
Sources (8)
- Age of the universe about 13.8 billion years: ESA, Planck
- BGV theorem; Vilenkin: inflation cannot go back forever, and it does not prove anything about God: Tufts Now, 29 May 2012
- Carroll: theorem is classical; causes do not apply to the universe; Guth thinks probably no beginning: Sean Carroll, Post-Debate Reflections, 24 Feb 2014
- Craig-Carroll debate, Greer Heard Forum, New Orleans, 2014: ReasonableFaithOrg (YouTube)
- Kalam argument history (al-Kindi, al-Ghazali, Craig 1979); Aquinas and contingency: Reichenbach, Cosmological Argument, SEP
- Hartle-Hawking no-boundary proposal; Feldbrugge, Lehners and Turok 2017 critique: Feldbrugge, Lehners and Turok, arXiv:1705.00192
- Maimonides on creation and eternity (Guide II:25): Maimonides, SEP
- Lemaître and Pius XII, 1951: The Thomistic Institute (YouTube) and Britannica, Georges Lemaître
