Questions From Readers

In the Mosaic Law, why were certain natural sexual functions viewed as making a person “unclean”?

God created sex, both for the reproduction of the human race and for the enjoyment of married couples. (Genesis 1:28; Proverbs 5:15-18) In chapters 12 and 15 of Leviticus, however, we find detailed statutes concerning uncleanness ascribed to seminal emissions, menstruation, and childbirth. (Leviticus 12:1-6; 15:16-24) Such laws given to ancient Israel fostered a healthy lifestyle, upheld lofty moral values, and stressed the sanctity of blood and the need for atonement for sins.

The Mosaic Law’s requirements concerning sexual functions promoted, among other things, the general health of the Israelite community. The book The Bible and Modern Medicine states: “The observance of the menstrual cycle with the prescribed period of abstinence from cohabitation proved to be an effective preventive against certain sexual diseases . . . and also a definite deterrent in the formation and development of cervical malignancies.” Such laws protected God’s people from diseases that might have been unknown to or even undetectable by them. Sound sexual hygiene increased the fertility of a nation that had been blessed by God with a promise of increase and prosperity. (Genesis 15:5; 22:17) The emotional health of God’s people was also involved. By obeying these laws, husbands and wives learned to control sexual passion.

The paramount issue involved in the types of uncleanness resulting from sexual matters, however, was the flow or loss of blood. Jehovah’s laws regarding blood impressed on the minds of the Israelites not only the sanctity of blood but also the special place that blood occupies in the worship of Jehovah, namely, in sacrifices and atonement for sins.​—Leviticus 17:11; Deuteronomy 12:23, 24, 27.

The Law’s detailed requirements in this respect, therefore, are closely related to human imperfection. The Israelites knew that Adam and Eve​—after their sin—​could not bring forth perfect children. All their descendants would suffer from the effects of inherited sin​—imperfection and death. (Romans 5:12) Because of this, parents could transmit only imperfect and sinful life, even though human reproductive organs were originally designed to pass on perfect life through the marital arrangement.

The Law’s purification requirements would thus remind the Israelites not only of their hereditary sinfulness but also of the need for a ransom sacrifice to cover sins and restore human perfection. Of course, the animal sacrifices they offered did not accomplish that. (Hebrews 10:3, 4) The purpose of the Mosaic Law was to lead them to Christ and to help them appreciate that it was only by means of Jesus’ perfect human sacrifice that true forgiveness was possible, opening the way to everlasting life for faithful ones.​—Galatians 3:24; Hebrews 9:13, 14.