Why did Hitler started out pro-religion and later in power anti-religious?

I don't know much about the history of Hitler's religious leanings or background but I know there has been a force of hatred and hostility towards Christianity from the very beginning. But Christ's Church has prevailed, the Christian faith has survived and flourished despite every evil poured out against it (and the evils that have attacked it from within also). Christ has preserved His people, His Church, and will until He comes again. From the blood of the martyrs has sprung the flowering of Christ's Church.