I want to say "Stop focusing on sin and focus on Jesus" here, but that may come off strong. Realize that the sins of the world have been dealt with at the cross. That means that the only sin left is the one the Holy Spirit convicts the world of. That is, disbelief in Jesus Christ (the Son of God). So, regardless of whether or not lesbianism is sinful in and of itself, the principle still stands that all sin has been dealt with at the cross. Our righteousness is not of ourselves, but in Christ. You don't come to God clean, or as some put it "You don't clean yourself before you take a bath." It is Jesus' blood that cleanses us from all unrighteousness, and therefore, not a matter of works, but grace. A lesbian can become a Christian just as much as a liar, thief, drunk, or prostitute can. When they accept Christ, they may or may not stop doing such acts immediately, but if they do not, it doesn't mean they are not saved, for their salvation isnt based upon them, but Christ. That's the radical truth. The fruit is the result of salvation, not the root of salvation.