Thanks for the question; it is one that I’ve given some thought to. My wife and I have five girls (now grown), and two grandaughters (brag). I have been an elder and full-time teacher for nearly 30 years, and I’ve not only faced your question personally, but from others, including family.
The first question is the more general one: “Should one in any way attempt to limit the size of their family?”
I would begin by pointing out that we live in a very selfish age, a time when people not only prevent conception for selfish reasons, but even avoid marriage out of selfishness. Nothing that is done from a selfish motivation is to be commended. Marriage and parenting requires humility, servanthood, and suffering. Having said this, not all motives for having children are wholesome, either.
Second, I would point out that children are a great blessing from God (Psalm 127:3-5), and thus one should consider limiting these blessings carefully. I am not saying that birth control is wrong; I am saying that one should be very careful to think this matter through. Many are those who have rejoiced over an “unplanned arrival.”
Third, in those cases in the Bible where a child was prevented and its prevention was regarded as evil, it was because there was the clear duty to have a child. I am thinking particularly of Tamar’s husband, Onan, who refused to raise up seed for his deceased brother, Er (Genesis 38:1-11). In this case, it is not birth control that is being universally condemned, but Onan’s refusal to father a child when this was his duty.
Fourth, I believe that the issue of limiting children comes down to a personal conviction before God. This means that we should not argue or divide over this matter, particularly in relationship to those with whom we disagree (Romans 14:1-6). The number of children we have (or don’t have) is not the measure of our spirituality. Having said this, “Whatever is not of faith is sin” (Romans 15:23). In the final analysis, it is a decision that must be reached by both husband and wife — it is a kind of jointly held conviction. If the wife were to feel strongly against birth control, I don’t think the husband would be wise to try to use his authority to impose his convictions on his wife. On the other hand, the wife needs to consider the convictions of her husband.
Fifth, I believe that 1 Corinthians chapter 7 may, by inference, address this matter indirectly. We know that marriage is from God (Matthew 19:3-6), as are our children (Psalm 127:3-5). In 1 Corinthains chapter 7, however, Paul encourages the Corinthian saints to abstain from their right to marry, because of the “present distress” (7:26). Marriage does divide one’s interests and devotion, and thus in order to serve God without distraction, Paul encourages those who are unmarried to seriously consider staying single, if they can do so “without burning” (7:1-9). There are occasions in which one can (and perhaps even should) forego some of God’s earthly blessings, for the sake of Christ. Paul, for example, declined to be supported, and chose to work with his own hands, for the sake of the gospel (1 Corinthians 9:1-23). If one were to apply this same principle to the bearing of children (as I personally think one can), then I think it is possible that a married couple may, for the sake of their service to God, choose to have no children, or to limit the number of children they have. It would be very difficult to take a family to the mission field where there were great dangers, and needlessly expensive to send and support a very large family on the mission field. Thus, for the sake of serving Him, the number of children might well be limited. One must be certain, however, that their motives are pure in this decision. Personally, my wife and I opted to limit our children to five (actually six — one died). As a preacher, it would be very difficult for people to have us in their homes if we became a larger family. Indeed, it was already difficult for some.
The second question you asked pertained to methodology. I have indicated that I believe birth control is permissible, perhaps even advisable, in certain circumstances, when done for the sake of our Lord. There are, however, various methods of birth control. I would be inclined to use those methods which prevent the sperm from uniting with the egg, and would not use any method which sought to destroy a fertilized egg. Some methods of birth control are abortive, and I would avoid these.