What does Paul mean in 1 Corinthians 7:1 that believers must be careful about regarding the opposite sex?

Les explains that Paul is writing to a congregation in the wicked city of Corinth, believers who came out of an abject, immoral, idolatrous background and were hung up on the marriage relationship now that it was Biblical rather than pagan. In paganism under idolatry, marriage did not amount to much and lacked moral integrity or fidelity, so the Corinthians were going off the deep end, asking whether it was right to marry. Paul therefore clarifies that “it is good for a man not to touch a woman” is not a prohibition on getting involved and getting married. Rather, in light of chapter 6, as believers, both men and women must be careful in their contact with people of the opposite sex in everyday experiences. Les says the Greek indicates a man should not get physically involved with a woman to excite the sexual senses. This does not mean eliminating shaking hands with women; even the early church granted the holy kiss, an embrace much like Middle Easterners still do.