In the hours before, and the moment of, Jesus’s death, He was confirmed innocent. Jesus lived a life without being guilty of anything. Although He was blamed for many things, He was nonetheless blameless.
The same ought to be true for us as followers of Jesus. You might bemoan the fact that it is impossible, since you have sinned and still do sin. How can one live guilt-free if one is in fact guilty?
The first answer to living guilt-free as a sinful person, is that Christ removes our guilt and makes us righteous. Just look at these description of what Jesus did for us sinners.
And you, who once were alienated and hostile in mind, doing evil deeds, he has now reconciled in his body of flesh by his death, in order to present you holy and blameless and above reproach before him,Colossians 1:21-22 (ESV)
you wait for the revealing of our Lord Jesus Christ, who will sustain you to the end, guiltless in the day of our Lord Jesus Christ.1 Corinthians 1:7-8 (ESV)
We can live a guilt-free life, because Jesus has removed out guilt for all the sins we have committed.
The second answer to living guilt-free as a sinful person, is that we live so as no longer to keep adding guilt to our lives. We pursue what is righteous, and holy, and honourable, and good. This is what our elders (1 Tim 3:2; Tit 1:6-7) and deacons (1 Tim 3:10) ought to model for us, but it is also what should characterise all saints—from the elderly widows and those who care for them (1 Tim 5:5-8), to the ordinary Christian living in this sinful world (Phil 2:15)
Live in such a way, that if anyone would want to accuse you of some wrong doing, they will have to fabricate false accusations. Live a guilt-free life—both by the Lord’s salvation of your sinful soul, and by your pursuit of obvious obedience.
For your obedience is known to all, so that I rejoice over you, but I want you to be wise as to what is good and innocent as to what is evil.Romans 16:19 (ESV)