Incorrect. He professed belief in "the spirit of Aryan man" not Christianity.
He persecuted the Christian churches the whole time he was in power, denigrated Christian teaching publicly, lived openly with a woman not his wife, and had Christian pastors like Bonhoeffer murdered and Christian pastors like Michael Faulhaber placed under house arrest.
He had every Jesuit priest in German imprisoned and most of them killed at Mauthausen.
He appointed as a Reichsminister of religion Alfred Rosenberg, who was an atheist dedicated to the replacemnt of Christianity with "Aryan humanism."
Rosenberg's 30 point plan for the German churches was to replace the Bible with Mein Kampf and the cross with the swastika.
If Hitler was a Christian, then so was Che Guevara.
Generally speaking, professing something means publicaly proclaiming to believe it. Perhaps, in the spirit of a polite discussion, you will document from Hitler's published writings and public speeches, something to document your claim.
Christians imprisoning and going to war against other Christians is pretty much the history of Europe. The Eastern and Western Popes were frequently at each other's throats.
Hitler was a lapsed Catholic who actively despised the Church.