I love Jesus. I have completely zero question within the Heavenly Trinity. Father, Child, Heavenly Spirit. how? the nonbeliever inquires. How can you believe something without any proof? Without any proof?! How can any intelligent person believe in fairy tales?
I'll tell you I believe in Jesus because I feel him. When I have experienced the reality of something, I do not need scientific evidence to believe it to be real.
I ask the atheist: How can you refuse to experience something that billions of other people have and which claims to be true? How do you deny your natural human curiosity to have experiences with so many others?
Suppose you have never tasted vanilla pudding. For all you know it tells you it tastes good. "Prove it", you say. "Just taste it, and you'll see" he replies. "I want proof first. I never believe anything that isn't scientifically proven." And so you deny yourself the joy of it while you wait for the "proof".
This is where I can outline all the miracles that Jesus has done in my life. Whenever I call on the Holy Spirit for comfort, I can describe my inner warmth and the hair on my neck and arms. Whenever I trust God the worry goes away. When faced with temptation, the victorious army Jesus provides when I ask him for help. It would probably take me a year to tell all the personal experiences I've enjoyed. Because of personal experience, I would be an arrogant fool who does not believe in Jesus.
I can relate to the physical therapy I received. The real cure for one woman's pancreatic cancer I've seen through Christian Science. Not only remission, but also the complete disappearance of the disease in a woman. But alas, the testimony will fail to meet the demand for scientific proof.
Some things can only be proved by experience. Taste Jesus and you will believe too. And the best part is that it is available to everyone! All you have to do is ask.