If everything in the universe shruck last night while you were asleep, how would you know it? In other words,  life in the physical world can be tricky.  And so is the life of faith.

Anyway, theists, in asserting their belief in God, are describing something real and moving in the depths of their being. Now, there is no direct empirical proof of that but there is evidence. For, one thing, theists often find that their faith results in a whole new attitude toward life which moves them off self to focus on the well-being of others, for a change.  Also, these same people organize groups to help others, like AA and the YMCA/YWCA.  Or oppose slavery, or big business' exploitation of the poor. Theists also build synagogues, churches and mosques.  Educate the young in community living (loving neighbor as well as God and self). If you want to knock around your head forever and not look at what religion has done (constructively) in the real world, then we'll be debating faith till the cows come home

Jesus, like many other Jews then and since, simply assumed the existence of God. (And questioned it on the cross, "My God, my God, Why have you forsaken me?")  For Jesus faith in God is essentially shown not in mere intellectual assent, but changed attitudes and a loving committment to the neighbor. "Except you change and become as little children, you will never enter the Kingdom of God" or "By their fruits will you know them"

The theist's faith surely is a potent remedy for existential anxiety or plain fear in the face of life's nasties - sickness, moral failure loss of loved ones, poverty, the loathing and ridicule of atheist sceptics, etc.  Fears , which are related closely to the big one - the fear of death. Now, you can say this faith is just a injection of novacane to take the edge off life - pie in the sky. Indeed, faith does help overcome the mind-numbing pain of life's nasties.   But it is does not take a person away from reality so much as assist him/her to face it seriously and squarely. And, coming back to where we started, the Christian theist looks at the cross of Jesus (life at its nastiest) and confronted by the presence of God in his soul, makes committment in faith there in the depth and mystery of his/her being.  Now this is not test-tube stuff  (science) but it does hit you where you really live.

Qball