I cannot speak to the issue of NFP vs ABC but I can speak to the issue of the sinful nature of artificial contraception in general. Forgive me if it has been addressed.
The biblical basis for the teaching comes from Dueteronomy 25 and Genesis 38.
*When brothers live together and one of them dies without a son, the widow of the deceased shall not marry anyone outside the family; but her husband’s brother shall go to her and perform the duty of a brother-in-law by marrying her. The first-born son she bears shall continue the line of the deceased brother, that his name may not be blotted out from Israel. If, however, a man does not care to marry his brother’s wife, she shall go up to the elders at the gate and declare, ‘My brother-in-law does not intend to perform his duty toward me and refuses to perpetuate his brother’s name in Israel.’ Thereupon the elders of his city shall summon him and admonish him. If he persists in saying, ‘I am not willing to marry her,’ his sister-in-law, in the presence of the elders, shall go up to him and strip his sandal from his foot and spit in his face, saying publicly, ‘This is how one should be treated who will not build up his brother’s family!’ And his lineage shall be spoken of in Israel as ‘the family of the man stripped of his sandal.’ (Dueteronomy 25:5-10)*Continuing a family name, raising a male heir and continuation of the blood line was so important to the ancients that a brother was required to raise up a son for his dead brother by his brother’s widow. That son would inherit his dead brother’s property but would not be counted as his own in spite of the fact that he had to provide for the child. The punishment for not doing so was public humiliation.
*Then Judah said to Onan, “Unite with your brother’s widow, in fulfillment of your duty as brother-in-law, and thus preserve your brother’s line.” Onan, however, knew that the descendants would not be counted as his; so whenever he had relations with his brother’s widow, he wasted his seed on the ground, to avoid contributing offspring for his brother. What he did greatly offended the LORD, and the LORD took his life too. (Genesis 38:8-10)*Onan did not fulfill his obligation under the law to raise up an heir to his brother yet receive a much harsher penalty than the perscribed loss of a sandal and a slap across the face. God took Onan’s life and the Catholic Church as well as orthodox Judiasim has always interpreted this as an indication of the gravely sinful nature of “Wasting seed.” Remember that in the Old Testament, loss of life was used to forshadowed New Testament mortal sin.
To understand the theological basis of why God took Onan’s life, we need to look at the nature of God, man and how human life is created.
God is pure spirit. He has no created parts, no weight, no size and no color. God is a purely spiritual being and he is immortal. Things like rocks and cars are purely created matter with no spirit. Man alone posesses both a created, mortal body and an immortal spirit made in God’s image. When man’s spirit seperates from his body he dies - his created body returns to the dust and his immortal spirit lives on. If the spirit is seperated from the body, the body is dead. It’s just that simple. Claims of out of body experiences aside, seperation of body and spirit (death) can happen only once.
If a spirit should seperate from a mans body when he is 70 years old, the man dies. The same happens if a child’s spirit should seperate from his body at 7 years old or an infant at 7 minutes old. No spirit, no life. If the spirit of an infant in the womb seperates from its body then we call that stillbirth or miscarriage. Now when man and woman unite in spousal unioun, man brings the sperm and woman brings the egg. They create the human body. God alone must bring the spirit, which he places into the fertilized egg at the moment of conception. This must be so because if there is no spirit, the egg is not alive. No spirit, no life. It’s just that simple.
In the act of spousal union, man, woman and God unite with man bringing sperm, woman bringing egg and God bringing spirit. All three unite in the act of spousal union to create a human life. This is why the Catholic Church teaches that man, woman and God are co-creators of human life and why life begins at conception. This is why Remember, no spirit, no life.
In spilling his seed, Onan denied God one of the greatest things he ever does, joining with man and woman to create a life. Onan denied God the ability to create a life and so God demanded his. God taking Onan’s life under the mosaic law makes perfect sense. It was a life for a life.
I sense that the NFP vs ABC discussion hinges on the husband and wife intent to deny God the chance to create a life vs being “open” to life and thereby not preventing God from participating in the process. I would love to hear further discusssion on this topic but the explanation above is basic teaching, in part, on the Biblical and theological basis for Curch teaching on the sinful nature of artificial birth control.
-Tim-