The writer of the book of Hebrews in the New Testament said that anyone who would come to God “must believe that he exists and that he rewards those who earnestly seek him.” (Hebrews 11:6b)
Of the things that we must do in order to receive the rewards for pleasing God this one seems the most basic. This requirement does not mention any pilgrimages, nor an obligation to observe a holiday or even to pray.
Because of the nature of faith in God, there is no proof that God does not exist or that God does exist. The existence of God must be accepted by faith. This does not mean that there is no evidence.
Some believe in God while others do not know believe that God exists.
Some who have found evidence about the existence of God now believe.
Some have honestly tried to be open to evidence.
Others have not been open to considering the possibility of credible evidence.
Many point to Galileo and say that when it comes to belief in God or belief in science they must choose with Galileo.
Galileo was not upset that the persons related to The Inquisition that examined him were officials in the Church. Those officials were also well versed in mathematics and astronomy holding the view of Ptolemy and Aristotle. They just would not consider the evidence even when repeatedly offered telescopes. If a person makes up their mind before-hand they will probably not change it, but seek evidence that proves their point.