What are we talking about in particular?
This?
Leviticus 18:22
'Do not lie with a man as one lies with a woman; that is detestable.
People love to quote this in opposition to homosexuality without really looking into it.
A more literal translation is that "man shall not lie with another man in the bed of a woman". This may sound a little weird, but consider that the rules in Leviticus are really intended for Levite priests, not the average Israelite. A woman's bed was considered a somewhat sacred place, with special rules including things like how to wash before, during and after taking a romp in it (with the woman). If the literal translation is correct, then the rule effectively says that gay sex is OK, just don't do it in the bed of one of your wives.
Many translations use the word "abomination," which is simply a mistranslation. "Unclean" is a better translation. If i recall (and it's been a while), it is the same word used to describe a menstruating woman. "Yucky" in Jewish thought, but hardly an "abomination".
The truth is that the Tanakh (the Old Testament) is vague on homosexuality. The New Testament is slightly less vague - Paul was almost certainly homophobic - but there is still no clear denouncement unless you want to read it that way.
All in all, it doesn't really matter. Just another example of cherry picking the Bible.
The problem is that the Biblical Hebrew the Old Testament largely comes to us in is a dead language. On top of that, the original Old Testament was written in a sort of compacted form of Hebrew that dropped a lot of information... especially little participles (a lot of that information was added after the fact in later years).
To see why this matters, it may mean that "man shall not lie with another man in the bed of a woman" could easily be "man shall not lie with another man as if in the bed of a woman". Those tiny little particles make a lot of difference.
My opinion is that the Bible does condemn homosexual behavior at all points (feelings, actions, etc.)...but I mean this is a book that condemns you to death for mouthing back to your parents, so it's not that big a deal. (Incidentally, yes, Leviticus 20:13 is essentially identical to 18:22 with just the added death penalty - which means it does speak of "in the bed of a woman".)
The question you have to ask yourself if you care about Biblical pronouncements is why follow these verses, but not the verses about shellfish or the rituals involving menstruation, etc. etc.? The Old Testament condemns hundreds of things, many of them rather stupid. Why pick these verses out as valid and not Leviticus 19:19 (KJV "... neither shall a garment mingled of linen and woolen come upon thee."), which basically forbids wearing wool-blended clothing?