Does this make him "not a Christian"? Hardly.
Does it disable his witness AS a christian? definitely.
I think deep in his heart he does see the contradictions, but simply refuses to recognize or explore the potential damage that it does, primarily because he has been involved with it for so long and has a difficult time denouncing all the good that he sees that it has accomplished in society. He is currently not actively involved, but if asked about it he will have nothing but good things to say about freemasonry. This does not make him right about the issue... but it doesn't make him non-christian either.
God? You post on FR? I had no idea.
You might try talking to your father before assuming how he feels and thinks.
You, and the rest of the people opining that you can't be a christian and a mason are really saying "you can't be a real christian like me and be a mason."
Didn't Christ say something about what happens to people that make judgements?
Regards.