What is faith he asked

He called on my birthday
We talked for a while
It was good to hear his voice
It made me smile
In the conversation
He asked what is faith
He seemed to be confused
He’s a soldier that’s received bad news
It’s hope I replied in the unseen
He laughed aloud saying you believe in invisible things
It made me laugh a little as silly as it sounds
But my belief in the invisible is what keeps me around
I pray everyday to a God that some can’t see
Probably because they’re looking in the wrong places unlike me
We ended the conversation and I moved on
But his question what is faith inspired this poem