From the Henry Center:

In many views of salvation, especially Protestant ones, holiness is often marginalized. It is seen as a desideratum, but only as a somewhat incidental state procured by the Cross, to be realized as a reality at death. This view is the result of an inadequate understanding of the relation of the Testaments to each other. It is clear in the Old Testament that the achievement of holiness as a replication of the character of Yahweh in this life is the fundamental issue. The writers of the New Testament assume that this is still the issue, so do not restate it. Rather, they move on to consider the ways in which the Incarnation and the Atonement of Christ address it. This is especially clear in the Gospels and the Epistles. The failure to recognize these truths is one reason for the observed lack of distinctly Christian character in our contemporary society.