It's a highly debated topic but from what I could gather so far being gay is a sin. BUT so is envy, pride, lust, greed ect. It could be argued that since we have no control (or at least only some control) over emotions that are associated with greed and envy AND we've already been forgiven for that, then it's completely normal to have homosexual tendencies/relationships. In conclusion, you can be a Christian but still be gay. (this is all only my opinion I could be wrong i'm still studying this topic)