In many pagan religions, sexual acts were part of worship. People believed they could control fertility (the ability to have children, crops, and animals) through sexual activity.
In some places, priests even served their gods without clothing. These practices were attempts to influence the powers of nature.
In the worship of the Lord, no form of sexual manipulation was allowed. God’s blessings cannot be gained through magical actions or human control.
For this reason, even the accidental exposure of the genitals was carefully avoided. Worship of the Lord had to reflect his holiness and purity.