If you do not have faith in God then you cannot believe in the words of God. Such doubting person cannot find peace in life & cannot attain to Divine consciousness. Doubting soul finds happiness neither in this world nor in the next, while the faithful one's attain peace & reach to God easily. Below verse of Bhagwat Gita explains that only.
"ajnas chasraddadhanas cha
nayam loko ’sti na paro
na sukham samsayatmanah" (Bhagwat Gita: Chapter Four verse 40)
"Sri Krishna said: But ignorant and faithless human beings who doubt the revealed scriptures do not attain God consciousness; they fall down. For the doubting soul there is happiness neither in this world nor in the next."
Here is a small story which explains the virtues of faith:
Once there were four monks. Three of the monks always used to spend all of their time in debating and talking about the existence of God & all types of intellectual pursuits. Fourth one was a simple man who had great faith in God & always used to sweep the floors of the temple. At the end, this simple man got enlightenment first. At this the intellectual monks asked their mentor how come the simple man got enlightenment first. At that their mentor responded, "When he was sweeping the temple floor, he was also sweeping the corners of his mind of all doubts". His firm faith in God without any doubt is the reason that he is able to attain to enlightenment first.