When someone disagreed with Paul's clear rules on immorality or angry disputes, the matters he deals with in Colossians 3.5–10, he is...
firm, as we see dramatically in 1 Corinthians 5 and 6.
Paul is preaching about activities based on sexual prohibitions laid out in Leviticus in the context of achieving holiness.
In other words, Witte claims that the Bible excludes premarital sex from its list of unlawful sexual relations (Leviticus 18) though Leviticus 18 is not the only such list, nor does Leviticus 18 claim to be exhaustive being devoted largely to forms of incest.
Some of the debate arises from the question of which theological approach is being applied.
Jewish marriage in the time of Jesus was a two-stage process.
First, there was a betrothal in which the man claimed the woman to be his only bride.