When I write, I try to represent the ordinary person in the pew, which means that, ironically, I'm qualified to write about prayer by being unqualified!
For me, prayer is not so much me setting out a shopping list of requests for God to consider as it is a way of 'keeping company with God.'
You are free to reject God. Make sure that you're really rejecting God, not some caricature of God that the church has shown you. But I, one, respect a God who not only allows us to reject Him but includes the arguments we can use against Him in the Bible. I respect that.
What I see in the Bible, especially in the book of Psalms, which is a book of gratitude for the created world, is a recognition that all good things on Earth are God's, every good gift is from above. They are good if we recognize where they came from and if we treat them the way the Designer intended them to be treated.
Most observers understand the difference between a committed Christian who accepts Jesus as a model for living and a 'cultural Christian' who happens to live in a nation with a Christian heritage. Most Muslims do not.
Most of the great books on prayer are written by 'experts' - monks, missionaries, mystics, saints. I've read scores of them, and mainly they make me feel guilty.
