It’s not possible to prove (or disprove) the God’s existence using the modern scientific method. This is because God, if exists, is not an object among other objects or a force among other forces. It’s something totally different and external to the observable world. Is it then reasonable to think that God exists? Are there some arguments or reasons for God’s existence?

Historical arguments
Philosophical arguments
Reasonable theists
~~Blind~~ faith

Historical reasons

Sources of evidence

Written documents
Archeological findings
Testimonies (only close history)

What this shows is that doing ancient history is HARD! Just as in Science, the different types of data don’t always agree very well, and we have to put things together the best we can. – A. Wall

Heck, cosmology is a more rigorous subject than archaeology, and there, until recently, we had this problem where many galaxies seemed to be older than the universe. – A. Wall

Bart Ehrman: “Serious historians of the early Christian movement—all of them—have spent many years preparing to be experts in their field. Just to read the ancient sources requires expertise in a range of ancient languages: Greek, Hebrew, Latin, and often Aramaic, Syriac, and Coptic, not to mention the modern languages of scholarship (for example, German and French). And that is just for starters. Expertise requires years of patiently examining ancient texts and a thorough grounding in the history and culture of Greek and Roman antiquity, the religions of the ancient Mediterranean world, both pagan and Jewish, knowledge of the history of the Christian church and the development of its social life and theology, and, well, lots of other things. It is striking that virtually everyone who has spent all the years needed to attain these qualifications is convinced that Jesus of Nazareth was a real historical figure.” – Did Jesus Exist? (2012), p. 4 - 5

Historicity of Jesus

If God is unreal, Jesus was history’s biggest fool or fake. – Peter Kreeft: A Shorter Summa (1993)

“Virtually all scholars of antiquity agree that Jesus existed.” – Wikipedia

Robert M. Price (a Christian atheist) who denies the existence of Jesus agrees that this perspective runs against the views of the majority of scholars. – Wikipedia

Michael Grant, a classicist, states: “In recent years, ‘no serious scholar has ventured to postulate the non historicity of Jesus,’ or at any rate very few, and they have not succeeded in disposing of the much stronger, indeed very abundant, evidence to the contrary.” – Jesus (2004)

Bart Ehrman (a secular agnostic) wrote: “He certainly existed, as virtually every competent scholar of antiquity, Christian or non-Christian, agrees” – Forged (2011), p. 285

Robert Barron: The Quest for the Historical Jesus
A. Wall: Comparing Religions V: Historical Accounts
A. Wall: Comparing Religions VI: Early Sources

Historicity of the Bible

Jesus in the Gospels often quotes the Old testament obviously considering it true.

Brant Pitre (Christian): The Case for Jesus: The Biblical and Historical Evidence for Christ (2016)
A. Wall: Some comments on Biblical History

Philosophical reasons

For

“The most incomprehensible thing about the Universe is that it is comprehensible.” – A. Einstein
Existence of objective universal morality or decent behaviour or fair play -> C. S. Lewis: Mere Christinanity - Book I
Argument from motion from the Five ways of Aquinas
Kalam cosmological argument
Leibniz’s contingency argument
Argument from desire

Against

Argument from the evil - an omnipotent and benevolent God should have eliminated all suffering. We observe plenty of man made and natural suffering in the world.
- Free will can not be achieved without allowing the possibility of doing wrong things.
- God can bring good through suffering - we can’t always (most of the time) see how.

Reasonable theists

C.S. Lewis (1898 - 1963) - English literature, originally atheist (Oxford)
John Polkinghorne (1930 - 2021) - theoretical physicist, theologian, and Anglican priest (Cambridge)
Fred Brooks (1931) - SW engineer and architect, computer scientist, author of The Mythical Man-Month (Harvard)
Russell Stannard (1931) - physicist, sculptor, written books for children (Open University)
George Coyne (1933 - 2020) - American Jesuit priest and astronomer
Donald Knuth (1938) - “high priest” 🙂 of computer science (Stanford)
John Lennox (1943) - mathematician, Christian apologist (Oxford)
William Lane Craig (1949) - philosopher, theologian, debater (USA, Munich)
Francis Collins (1950) - genetisist, led the HGP (Yale)
Larry Wall (1954) - language designer and BDFL
Bishop Robert Barron (1959) - high Catholic priest and philosopher (LA)
Rosalind Picard (1962) - engineer (MIT)
Edward Feser (1968) - philosopher
Karin Öberg (1982) - Swedish professor of astronomy (Harvard)
Aron Wall (1984) - theoretical physicist (Cambridge)
Luke Barnes - theoretical astrophysicist (Australia)

and many more.

Reasonable atheists

Richard P. Feynman - physicist
Stephen Hawking - theoretical physicist, cosmologist (Cambridge)

Faith and providence

Faith in the sense that it’s something that comes at the far edge of reason. Like when you know a person for a long time and then he tells you something you can’t verify. You have to decide whether you believe him or not.

Providence perceivable in history (e.g. Scriptures) and in one’s own life.

Why should they be impartial, what is being impartial, when the whole world is at war about whether one thing is a devouring superstition or a divine hope? I do not pretend to be impartial in the sense that the final act of faith fixes a man’s mind because it satisfies his mind. But I do profess to be a great deal more impartial than they are; in the sense that I can tell the story fairly, with some sort of imaginative justice to all sides; and they cannot. – Chesterton: The Everlasting Man