I can't figure out why people think it's possible to be perfect? Only Jesus was perfect. That indicates every one else is imperfect. Only legalists demand perfection, because legalists demand conformity to their religious ideas, since it only requires an *external observance,* and not true perfection. It is then thought that by following somebody's idea of perfection that perfection is accomplished by external observance on its own merits.
Clearly, that is not true. Anybody can observe the Sabbath Day. That can be done by a murderer or by an adulterer. External observances do not accomplish perfection. (Not that we are even under a Sabbath Law. That Law was given before final redemption was won through Christ, and only for the Jews.)
So who's standard are you going to require? Are you going to require that Christians *never* hate, *never* have lust, *never* be covetous, or *never* even be argumentative or demeaning? Obviously, the objective is to *try* to be all good things.
But the expectation is that we *overcome* our base natures by a long regular process of choosing to abandon our temptations to selfishness in order to draw upon Christ's strength in our weakness. That requires an admission of our weakness, of our imperfection. And it is an admission that we must rely on Christ regularly for our spiritual cleansing.