Catechesis: Sixth Commandment

Not only is the outward act of adultery forbidden, but also every kind of cause, motive, and means of adultery. LC I:203

Everyone must live chastely himself and help his neighbor to do the same. LC I:205

He created man and woman separately, as is clear. This was not for lewdness, but so that they might live together in marriage, be fruitful, bear children, and nourish and train them to honor God. LC I:297

For where nature has its course—since it is given by God—it is not possible to remain chaste without marriage....Yet God’s grace is also required in order that the heart may be pure. LC I:212

Therefore, all vows of chastity outside of the married state are condemned by this commandment. LC I:216

For harmony is one of the principal points that enkindles love and desire for chastity, so that, where this is found, chastity will follow without any command. LC I:219