Sarahkka: There are a few issues in your argument. First, replacing "gay", "lesbian", and "homosexual" with "black", "hispanic", or "native" is not logical. When I say that homosexuality is a sin, I'm referring to specific acts that are a result of giving into temptation. Race is something that you are born with, and have no control over. It is not an action, thought, or desire. Scripture indicates that, in regards to race or social status, God views all people as the same. I would refer you to Acts 17:26 and Job 31:13-15. These are just a two examples, but I believe it is evident throughout Scripture.
Secondly, God's Word does not condone slavery, at least not in the modern sense of the word. When most people today think of slavery (including myself), we think of slavery in the modern sense of the word. We think of New-World/Western slavery, and Biblical slavery was nothing of the sort. In the Old Testament, slavery was primarily something that a person entered into voluntarily, but there were many laws regarding treatment of slaves to protect them. Even non-Jewish cultures had a different definition of slavery than what you'll find today. In the New Testament, slavery among Christians looked more like the Roman model of slavery, and Paul not only encouraged a respectful slave/master relationship, but also encouraged voluntary manumission of slaves.
The argument is very logical in that, just like racism, homophobia denies a group of people the same rights and freedoms as the rest of society based on their sexual preference. And I do argue with you that homosexuality is a choice or an action. I think sexual preference is part of the essence of a person's nature. To suggest that someone should repress such an important part of themselves and "choose" not to be gay is abhorrent.
Because what I think you are suggesting is that living that kind of lie is acceptable to your god, but open acknowledgement of love between two consenting adults is not? I have trouble reconciling that with the Christian message of tolerance and acceptance.
The next part of your argument is trickier for me, as I am not a Christian and have nowhere near the knowledge of your version of the bible that you do, but I think this boils down to interpretation.
The following is meant to be a bit of humour, but does have a point - the bible tells us to do a whole lot of things that were probably pretty important 2000+ years ago, but are of questionable relevance today. Perhaps declaring an entire group of people as sinners and miscreants based on their sexual preference should be dropped the same way that "only wearing one fibre at a time" or "not planting two different crops in the same field" kind of biblical instruction has.
https://allthingsqueer.co.za/archives/religion/60.html