But the Pharisees and the teachers of the law who belonged to their sect complained to his disciples, “Why do you eat and drink with tax collectors and sinners?” Jesus answered them, “It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners to repentance.” – Luke 5:30-32 

If the popular Christian doctrine that “all men have sinned” held any merit, Jesus would have said he was here for everybody, because everybody – being sinners – would have needed Jesus.

Instead, Jesus distinguishes the sinners from the righteous.
He acknowledged the existence of righteous people – as opposed to the sinners on whom he was focused on. The righteous make it by their own faith and righteousness whereas its the sinners, “the lost sheep” for whom he came. This theme is echoed in many other places in the Bible, especially in the Old Testament, comparisons are made between the “righteous” and the“unrighteous”, “wicked”. The best example would be the entire chapter of Ezekiel 18. The righteous are contrasted with the unrighteous, in terms of their behavior and the way they would be dealt with.

IMO, being righteous implies refraining from evil and doing good habitually, while of course, believing in God. When a “righteous” man slips by sinning, he would repent and seek forgiveness from God (Psalm 51)… as opposed to an unrighteous man who does not repent and goes on to justify it and being mindless of God.

The prayer that Jesus taught his people does not echo Pauls ideas about all men being sinners and the need for sin sacrifice. Instead it teaches that one needs to forgiving in order to be forgiven by God. Pauls erroneous teaching that “all men have sinned” is a foundation for the doctrine of “sin sacrifice”. It takes away the need for repentance on a daily basis through prayer. i.e – “forgive us our sins, as we have forgiven those who sin against us”.

God knows best.