If you have to lie to have your faith, don't bother. And if you believe lying is allowed, don't call yourself a Christian since you aren't one.
All Christians are sinners. They come to that faith with that as the requirement. That requirement never leaves them; or very rarely. You may have heard of saints? They are the uber-rare exception to the
immense-rule.
The rest of them are sinners...ALL of them! Their sin however does not submit the Christian New Testament to democratic revision. There is no power of redaction via numbers. In the New Testament there are prescriptions of all types for this type of sinful behavior and that type of sinful behavior. Homosexuals are no different. Christians are urged to reach out to them with compassion "making a difference".
Venial sins vs mortal sins are what's being discussed particularly with respect to so-called "gay marriage". Being a homosexual is a venial sin; its mendable, forgivable, deserving of tolerance and compassion. HOWEVER, enabling a homosexual to call what he does "normal" or to spread that idea to others, particularly an entire culture or settlement of people is UNFORGIVABLE. The prescription for that is the eternal death in the pit of fire..