"I was a Christian for 25 years."
During your time as a Christian, did you know the Lord? If you say that you did know Him, you are admitting that God is real. If you say that you thought you did, then you didn’t, and you were never a Christian. You faked it all that time. But you are not alone. Many, if not most atheists have had false conversions and that’s why they are so adamantly anti-Christian. They heard a false gospel that said that Jesus gives joy and peace and fixes problems, and when what they think is Christianity didn’t deliver the promised goods, they became disillusioned and often bitter.