Most Christians have been taught that Jesus lived a sinless life. Hebrews 4:15 categorically claims Christ's sinlessness in the face of the very sort of temptation that we all face. This claim of sinlessness is, in large part, the basis for soteriology (theology of salvation): Jesus was the sinless sacrifice upon whom God could rest the sin of the whole world. Jesus' crucifixion seems to loose its meaning if his sinlessness cannot be established.
From whose perspective was Jesus sinless? Certainly not from the perspective of the ruling religious elite. They were constantly pointing out the various sins that Jesus was committing: working on the Sabbath, cheating on taxes, defaulting on tithing, associating with prostitutes and tax collectors. These were not just minor grievances that the Pharisees had against Jesus – there were definite laws pertaining to these things and restrictions on association held significant consequences (think cleanliness laws pertaining to Samaritans, menstruating women, and diseased individuals). Nothing to get too bent out of shape with this, in fact sticking to the nasty Pharisees is something revered in Jesus ministry. The religious leaders of the time have been constructed as these nasty self-righteous control freaks. It is convenient to forget that they were charged with preserving what was considered to be the most authentic religious expression of faith in YHWH in the face of the oppressive rule of Rome.
It is also convenient to forget the hegemony that these leaders accrued from the Jewish people of the day. Certainly as within every religious expression 100% compliance was far from normative but other historical documents reveal just how closely most of the population was able to follow the Pharisaic prescriptions. In other words, people generally considered the regulations imposed by the religious leaders of the day to be an adequate standard by which to model their lives. All this was in the face of a fairly democratic approach to religious orthodoxy. It was common to have contentious issues debated openly in the synagogues. Although, it was obviously a restrictive society it is difficult to claim that the people lived in religious oppression. Religious apathy perhaps?
According to whose standards would someone need to live today in order to be considered sinless? Which church conference guide would be accepted as accurate enough? My suspicion is that Jesus would have very much the same evaluation today as he did from the religious leaders of his day. He would break many of the conventions around which we have built our set of morals. And we would denounce him for that – not just our religious leaders but we ourselves.
So does Jesus just get to rewrite the moral standards arbitrarily and 'get away' with being known as sinless? Yes in some ways he does. Jesus understands morality differently than most people do. In Jesus' teaching it is clear that he constructs morality according to principles not according to specific regulations. Unfortunately most of our rhetoric about Jesus does not reflect this – in fact most often we use specific instances and teachings to uphold our particular moral regulation rather than discover the nuances of how a Godly principle should be applied.
As a result it is not very helpful for us to talk about Jesus as being sinless. He clearly broke the moral norms of his day. To say that Jesus never contradicted any Godly principles might be more accurate but it isn't very useful for us since it does not allow us to defend some of the hard fought moral codes we have adopted. So Jesus remains this sinful sinless man.