Ignoring the faults of others does not secure forgiveness for you or them

It is good to forgive those who sin, but it is better to do what you can to help them stop sinning. While these are not mutually exclusive, too many people find comfort in forgiving another person for sin while refusing to do what they can to help them stop. This disconnect reveals the motive for such behavior to be selfishness, not love. People incorrectly think that if they ignore the faults of others, God will ignore theirs. God does not and cannot forgive willful sin.¹ While forgiving others of the willful sins for which they have repented is necessary in order for God to forgive you of the willful sins of which you have repented, God will not forgive you of willful unrepentant sin, even if you forgive the willful unrepentant sin of others.

The life of a person who is living in sin will not improve until and unless they stop sinning. Your forgiveness will not change their lives. Forgiveness is not given because of confession of sin alone; it also requires cessation of sin:

And again, believe that ye must repent of your sins and forsake them, and humble yourselves before God; and ask in sincerity of heart that he would forgive you; and now, if you believe all these things see that ye do them. (Mosiah 4:10)

By this ye may know if a man repenteth of his sins— behold, he will confess them and forsake them. (D&C 58:43)

You can choose to forgive those who have not repented, but that doesn’t mean God will.

Forgiving others by ignoring their bad behavior does nothing to prevent the consequences of that behavior. Your willingness to overlook their decisions until now does nothing to help them encounter the blessings of obedience to something better. If you love a person who sins, you will do what you can to help them stop.