For the Christians who read this, I've been wondering about this myself. I'm a devout Christian and I always will be, but at the same time, I'm bisexual. I was reading the Bible (NIV Version) and I happened upon the following verse: (Leviticus 20:13)
"If a man lies with a man as one lies with a woman, both of them have done what is detestable. They must be put to death; their blood will be on their own heads"
The way I interpret this is that if the two have sex, then the relationship is sinful. I don't think the feeling of being gay is sinful itself. If you're a Christian, then a physical relationship should be considered wrong. I know there are atheists on here who are going to reply negatively to this. So, I'm just saying this in advance that no amount of arguing and complaining is going to change my beliefs.
As for God making us the way we are and where it concerns sexuality, I believe that it is a mix of God's design and habit. I think homosexuality is a habit that develops over time. God just made it where we can make our choice on what sexual habit we make. I'm not meaning to contradict Leviticus 20:13, I'm just saying that I don't think there is nothing inherently wrong with falling in love with another man, but it's when it gets physical that it gets sinful. Granted, I lean more towards women than I do men, but I can't deny or ignore the other half my sexual orientation being there. Rather than trying to fight that habit, I've just learned to accept it as a part of me that I developed by habit.