1 Corinthians 7:5

Evidently the Corinthians, at least some of them, had concluded that since they were "spiritual" they did not need to continue to have sexual relations as husband and wife. Another less probable situation, I think, is that there were some married Christians in the church who were overreacting to the immorality in Corinth by abstaining from sexual relations with their mates. For whatever reason, Paul viewed this as depriving one another of their normal sexual needs and urged them to stop doing it. Husbands and wives should commit themselves to honoring the spirit of mutual ownership that these verses describe.

There are legitimate reasons for temporary abstinence, but couples should temporarily abstain only with the agreement of both partners. When there are greater needs, spiritual needs, the couple may want to set aside their normal physical needs. However they should only do so temporarily. Laying aside eating (fasting) or sleeping (watching) temporarily to engage in more important spiritual duties (e.g., prayer) is similar.

"Three conditions are required for lawful abstention: it must be by mutual consent, for a good object, and temporary." [Note: Ibid., p. 134.]

Normally we think of sexual activity as an indication of lack of self-control, but Paul also viewed the failure to engage in sex as a lack of self-control for a married person.