You say, "The belief that there is some benevolent God in heaven who basically wishes good of me and is going to help me be happy if I pray him. This caused me lot of harm. Emotionally and otherwise to my life itself. –"
First I would like to say I am sorry that someone in your Christian past taught you something that Christians do NOT believe. A cursory study of Reformed Theology would show you that actual Christians do not believe in such a God as you have described. There are prosperity preachers and other aberrant teachings that spread vacuous lies and untruth under the guise of Christianity- and they burn like wildfire through many under-educated congregations.
Being angry about it is frustrating, infuriating, and rather pointless as it only hurts you and keeps you from moving forward. At some point in each of our lives we have to make a choice to only own our own stuff if we want to move forward emotionally, psychologically, and attain a level of peaceful happiness.
Each one of us must choose what we believe. A lot of people think that indoctrination trumps choice but it does not if you are even a modest thinker.
You can choose today to let it go. You can acknowledge it, and accept it as part of your past and move forward with your studies and practices in Buddhism unfettered from the anger your feel regarding your previous religious experience - accept that the people who are part of your past who still practice their faith are, like you, seekers along the way trying to find their own place in the universe and their own understanding of peace, joy, happiness, and love.
We are complicated beings, but the vast majority of people all pretty much want the same things.
Moment by moment we all choose how we will respond, how we will think, how we will love or withhold love - keep choosing peace, love, unity, and joy.