Jesus: " . . . I will in no wise cast out." Really?

You might find this to be TL;DR.

I wanted to answer someone who posted a Christian salvation message, altar-call style, on Facebook. He wrapped it up with this:

John 6:37:
"All that the Father giveth me shall come to me; and him that cometh to me I will in no wise cast out." (KJV)

My life's experience proves that this is out and out bullshit.

When you've been saved as a child, and as a young adult you've become agnostic but still want to believe, and you want to sing, you sing in a church choir.

I made a friend in that choir. I felt close to her - not super close, but I trusted her. She seemed true. One day we were having coffee and in one of the most regrettable whims of my life, I came out to her. I felt no fear.

After our next rehearsal, the director caught my eye and waved me over. He told me that it had come to his attention that I was a homosexual. As such, he said, he knew that my claim to worship, as a member of this choir, was false. He dismissed me from the choir.

Having been rejected by a representative of Christ (as I saw the director), I left that church flat. I never went back.

So what's this bullshit about "him that cometh to me I will in no wise cast out"? If this god knew my heart, he knew I was a true believer - questioning but studying, listening in church, contributing my thoughts in bible study - he would've known that singing in the church choir was an act of sincerity.

So why did he in fact cast me out via his representative?

This has been bugging me for months. I usually manage not to go off like this when I read altar call sermons on FB. This one is different - probably because my experience contradicts Christ's words. I will always hold my life's experience over words written eons ago, based on tales told over and over and coming through to future generations as clearly as a game of telephone.