It is a reasonable postulation. God either exists or not. It is binary.
If God does exist, a man cannot be a communist.
If God does not exist, man will exalt the state to the same level as God. Power hungry men will demand they be revered as God and control everything you are. Look at every communist state - NORK (Kim dynasty), China (Mao), USSR (Lenin, Stalin, et al).
Agree so far.
If God does exist, a man cannot be a communist.
Umm... no, I don't see that. A person could believe in God and still think "Well, Jesus said render unto Caesar that which is Caesar's, so a government that gives individuals no legal rights or private property has nothing to do with my acceptance of God's dominion over my soul, and me following His commandments." There are no Biblical commandments that I know of that a Communist could not follow. Now, a Christian who refuses to state that there is no God is not a good Communist, but a Communist can be a good Christian.
If God does not exist, man will exalt the state to the same level as God.
Oh, they do that anyway. Look at all the European kingdoms who simply declared their King as God's representative on earth and then garnered as much power as they could, all in God's name, of course.
Power hungry men will demand they be revered as God and control everything you are.
Yep. Every European King, ever, and every cult leader too. They just declare themselves His representative and, that little detail taken care of, proceed as they see fit.
Look at every communist state - NORK (Kim dynasty), China (Mao), USSR (Lenin, Stalin, et al).
Look at Mohammed's legacy. Hey, say what you will, he believed in God.