This is an issue that has concerned me for quite a while now. I honestly don't feel like I could take the Church's word as authoritive on many ethical issues, because it seems like they have changed over time or were just influenced by politics.
Poppycock! You don’t want to take the Church’s word because it doesn’t sit well with you. For your foundationless statement to have any meaning, you would be required to support it with some evidence.
For example, western society mostly condemns slavery and polygamy, and as of right now, the Church does as well.
So, they agree and this is a bad thing? I must confess confusion as to why you are comparing Eastern Christianity with Western thought. You are bound to find friction. Why did you use the word “mostly”?
However, when I look at the history of the Church, it doesn't appear so like it always has. The New Testament never condemns polygamy,
Really? So I suppose when Jesus was talking about divorce and marriage, the fact he used the word “wife” rather than “wives” means nothing?
1 Corinthians 7:2: “Nevertheless, because of sexual immorality, let each man have his own wife, and let each woman have her own husband.”
Ephesians 5:31: “For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh.”
Monogamous marriage teaches us the type of the relation Jesus has between himself and His bride, which is the Church. We know the Church is he bride, communally as one in a singular sense, not a plural sense of wives with each person within the Church, so is the relationship in marriages.
Not only this, but if a man has sex with someone other than his wife (singular) he commits adultery, which we all know is sin. So, if the Church supported polygamy, it provoked men to commit adultery, which it clearly condemned. This doesn’t make any rational sense at all. The entire idea is absurd.
the Church supported slavery/serfdom for quite a while
More modernist poppycock!
and it just seems like the only reason the Church condemns those things now is because it wants to appeal to modern society,
Is this the same Orthodox Church which has remained unchanged for many a century?
and thus, the Church--which is supposed to be the unchanging pillar of the truth--has changed over time in order to match contemporary western society's ethics.
No, it has not.
As a result, I find myself very skeptical and unconvinced by the Church's "stance" on many issues. Thoughts?
Yes, stop listening to contemporary ideologues and their ideas of what they want to have happened over the centuries rather than what actually did.