As Jesus hung on the cross He prayed, "Father, forgive them; for they know not what they do" (Luke 23:34). Rather than seeing forgiveness as a welcome benefit of ignorance when it comes to judgment (which Scripture does not support), see how the love of Jesus for sinners combined with His knowledge of them prompted Him to show compassion on them. Jesus knew the deceived, envious hearts of those who plotted His murder, yet He was compassionate to intercede on their behalf before His heavenly Father and ask for forgiveness. Often we lack both love towards others and knowledge of what people are going through. Being born again by faith in Jesus, we are aided by the Holy Spirit to consistently show compassion on others when we naturally know little and love even less.
A recent study of the first chapter of Romans was instructive to me in considering the prayer of Jesus to forgive those who knew not what they were doing. They did not believe Jesus was the Christ, the Messiah God promised to send to save His people from their sins. Had they known and been convinced Jesus was the Christ, it follows they would have treated Him differently. Though the Pharisees had great knowledge of the letter of the Law of Moses, without faith in Jesus they were blind to His divine nature: they had eyes that did not want to see and so they could not see; they closed their ears to the truth Jesus proclaimed and thus could not hear. Their self-inflicted blindness, deafness and hardness of heart was in conjunction with the fulfillment of scripture (Isaiah 6:9-10) and God's sovereign plan to redeem the Gentiles as well as Jews (Romans 11:7-11).
In Romans chapter 1, Paul explained God's wrath is revealed against all ungodliness and unrighteousness of men, to all of mankind to whom He gave His only begotten Son Jesus. God's judgment of sinners is seen by giving man over to uncleanness through the lusts of their hearts (ver. 24), to vile affections or passions (ver. 26) and gave them over to a debased mind (ver. 28) to commit all manner of sin. Though man is without excuse before a righteous God for sin (Acts 17:31-32; Romans 1:20-21), God provides knowledge how and why people are morally adrift today with consciences unfit for purpose--like a clock without hands that cannot be read. Knowing this about the state of humanity, it provokes compassion within me to intercede in prayer on behalf of those who sin and think they do well, who know not what they do. Since Romans was written to Christians, it is also a warning of the consequences should we suppress the truth of God, refuse to glorify Him, give Him thanks, or dislike to retain God in our knowledge. God is not willing any should perish and that all should come to repentance, and thus shows compassion by His patience and continued proclamation of His truth.
Ignorance of sin or judgment does not exonerate a soul, but it ought to stir compassion in our hearts for the drifting, lost and perishing. It would be a great shame to use Romans 1 or other passages of Scripture as ammunition to take shots at others in judgment rather than the humble consideration of the state of our own hearts and minds with repentance. Should God give us over to a debased mind, how could we make one wise judgment? Let us be those who proclaim the truth of God, glorify Him with thanksgiving and remember His goodness, love, and compassion to us always so we might be a light to those in darkness, knowing we too were once in such a state. God demonstrated compassion to open our blind eyes and closed ears, give us new hearts and renewed minds, and let us extend the same grace to others without restraint.