Let us go a step further. In the human dream of a perfect world, holiness is always visualized as untouchability by sin and evil, as something unmixed with the latter; there always remains some form or other a tendency to think in terms of black and white, a tendency to cut out and reject mercilessly the current form of negative (which can be conceived in widely varying terms).
In contemporary criticism of society and in the actions in which it vents itself, this relentless side always presents in human ideals is once again only too evident. This is why the aspect of Christ's holiness that upsets his contemporaries was the complete lack of this condemnatory note-- fire did not fall on the unworthy, nor were the zealots allowed to pull up the weeds they saw growing luxuriantly on all sides.
On the contrary, this holiness expressed itself precisely as mingling with the sinners whom Jesus drew into his vicinity; as mingling to the point where he himself was made "to be sin" and bore the curse of the law in execution as a criminal-- complete community of fate with the lost (cf. 2 Cor. 5:21; Gal. 3:13). He has drawn sin to himself, made it his lot, and so revealed what true "holiness" is: not separation, but union; not judgment, but redeeming love.
Is the Church not simply a continuation of God's continual plunge into human wretchedness; is she not simply the continuation of Jesus' habit of sitting at the table with sinners, of his mingling with the misery of sin to the point where he actually seems to sink under its weight? Is there not revealed in the unholy holiness of the Church, as opposed to man's expectation of purity, God's true holiness, which is love, love that does not keep its distance in a sort of aristocratic, untouchable purity but mixes with the dirt of the world, in order to thus overcome it? Can, therefore, the holiness of the Church be anything else but the bearing with one another that comes, of course, from the fact that all of us are bourne up by Christ?
--Introduction to Christianity (1968), Pope Benedict XVI