There are two calls that can be described when talking about calls of Christ (God). The first is a general call, one that goes forth from those who preach the Gospel. This call is general because the Gospel is preached to everyone without discrimination. The second call is specific to only certain people that God chose before the foundation of the world to become heirs of His kingdom.
These individuals receive this specific call through the work of the Holy Spirit during the preaching of the Gospel (first type of call). This second type of call cannot be resisted, for when the Holy Spirit calls, those chosen by God answer.
God does not restrict this calling to only those who have lived perfect lives, for there isn't a person who has lived or will live that could live a perfect life except for Jesus Christ. Therefore, this call goes out to those whom God has chosen and not to those who have any merit, for no one has any.
There is no sin too big or offensive that this call cannot conquer. It brings into the kingdom of God sinners from every vein of life. People who used to live in sin; lust, murder, adultery, thieves, liars, those living out their sinful desires within the LGBT community, haters of God, and many others. None of these sins is enough to keep you from being able to resist the calling of the Holy Spirit.
However, all of these sins must be repented of and laid at the feet of Christ. We must repent of the things that keep us from Him, even the things that the world has worked so hard to make acceptable. Our lust, both sexual and our desire for more of everything. Our hatred of our fellow man. Our desires to pervert God's design for gender and sex, these too must be repented of, even though the current culture tries to make them "natural".
The Church has been called to preach the Gospel and through doing so, the Holy Spirit works in the hearts and minds of those who hear to bring about salvation and repentance. There isn't a sin too great, not even for those who have answered the call of Satan (see previous post).
Let us love one another as Christ loves us and has called us to be lights in a dark world. May we be bold to stand for truth, knowing that doing so is to be loving. For allowing someone to believe a lie is only going enable them and encourage them to continue living in sin.