But then there shouldn't be the wide diversity of Christian sect that we see
1. Just to make sure that you aren't saying this - you are no longer arguing that the position on homosexuality is up for interpretation, nor arguing that the wide variety of Christian sects that we see are due to various beliefs about the meaning of the scriptures regarding homosexuality, correct?
2. It is precisely what we would expect. Once you get beyond the direct words of the text, how to apply them does devolve into a matter of interpretation, which well-meaning people can disagree over. Homosexuality, however, is not one of those issues - it is covered in the direct words of the text.
If it's just the Bible, there seems, at least you are implying that, there is but one interpretation that is "right". So which sect of Christian is right? Why are the others wrong?
:shrug: my bet would be that no sect has it perfectly right, and that many have some parts more right and others more wrong relative to each other (Catholics are likely better about sticking to Jesus' teachings on divorce, Calvinists perhaps on rejecting implicit faith). Once you leave exactly what the New Testament says, you have to pray and faithfully try to apply it to questions it does not address. Heroin, for example, isn't directly addressed, but a Christian could faithfully apply the verses to treat your body as a temple, obey the laws of the land, and avoid alcohol (which is a drug) abuse to the point of drunkenness. The Bible doesn't "say" whether or not to do heroin, but Christians can say with some degree of surety what its' authors
would say about whether or not to do heroin, while recognizing that they don't have the full surety because it remains an interpretation of the guidance of the Scriptures.
That is not the case with homosexuality. The Bible there is direct and clear. For our example, it is as if the text were to say - in multiple places - "Don't do Heroin". "God doesn't want heroin in your body". "People who do heroin are screwing up, don't follow that path." It's a direct rejection. The extent to which you are interpreting the meaning of the text is pretty much shrunk to nigh-nonexistent. You really can't look at the verse that says "Do not do heroin" and "interpret" it to mean "oh, this says it's okay if we do heroin", and yet claim to be faithful to the text.