I have no right nor responsibility to “forgive” someone who has not hurt me. If my brother or sister chooses a life that is different than mine, s/he has not hurt me in any way that is direct and measurable. S/he might offend my sensibilities, but Elder Bednar pretty much destroyed that as an excuse for feeling like I need to forgive him/her.
Since we believe all of us are brothers and sisters in a very real way, where is the need for human "forgiveness" of others whose actions or beliefs naturally would offend us? My stake is full (word chosen intentionally) of sinners who attend church regularly - and I feel no need to “forgive” them for their sins or have them forgive me for mine. I’ll leave that issue in God’s hands - even though I accept the “sinner” label for them and me.
In summary, the many “sins” that are obvious to us are no different in my mind than the sins that so easily beset me and of which I can’t seem to repent fully. If the Lord will grant me mercy in my inability to let go completely of my own pet sins, why should I not grant that same mercy to others whose sins simply are different than mine? I think if we really understood how little we deserve what we receive as we fail to live up to God's ideal, we would be more likely to cut others slack whose lives don't conform to our own perfect ideal.