For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
The church did not originate the idea that homosexuality is wrong; God did! The fact is that all commands from God are based on His own opinion, before matter even came into being.
God created ONE man and ONE woman to be together. Not multiple on either side. God DID NOT created many women for a man, ONLY one. All this is noted in the first three chapters of Genesis.
God did not give Adam a man. He only ordered multiplication of life forms based on union.
NOTE also that the rule of not eating of the Tree of Life was NOT given to the woman, but the man.
The point is, the Church is the express of Christ and his Father, not other sources.