I have always loved mathematics. It is one of the main reasons I studied engineering in school. Simple math can even give us insights to the effects Christianity and Islam are having on the world today.
My oldest son and I attended an Evangelism Explosion seminar a few weeks ago. In this seminar the instructor sort of went off on a tangent and shared something I have never heard shared in church before. He said that years ago he was teaching a young marrieds Sunday School class and he was teaching them through the Song of Solomon. During this teaching a young woman asked a question he was not prepared to answer. She asked, "How do you know how many kids you should have?"He told her, "Let me look that up and get back to you." He then went searching for an answer in the Bible. He then told us what he found. He said, "Class, you know what? You won't find anywhere in Scripture that you should limit the number of kids you should have. In fact, it says in Scripture that children are a blessing and the more you have the better."
Sadly, I know many Christians have never heard this before. And the way of the culture is to maybe have children but not too many. Most Christian families have followed this cultural norm not knowing any better. I know I was very close to making a decision that would have cut me off literally from having more children. And only by God's grace did He alter my course of action and here I am six children later and hoping God will give us the privilege of raising more.
Ultimately it is God who opens and closes the womb. And I know there are many who desire to have children but are not able and for whatever reason God will many times decide to keep the womb closed. We see in the Old Testament many very godly women whose wombs were closed for a time. But we never see in Scripture God telling someone to sterilize themselves or take some action to prevent conception. God's word clearly states that "children are a blessing" and certainly we see throughout Scripture and in our own personal experience that God does withhold blessings from his people when they turn away from His desires and/or pursue other things instead. In other words, man can reject God's blessings by his own free will and actions.
In this culture it seems very strange for a married couple to leave their reproductive system fully natural and capable as God designed it. And for some it is a very scary idea to let God decide how many kids you will have. But isn't that what faith is all about. Trusting God, because He has proven to be trustworthy and He is God afterall, even when our own logic or the worlds wisdom around us tells us to do something else? And is it not the purpose of the Christian to live for Jesus and not himself?
Another thing you do: You flood the LORD's altar with tears. You weep and wail because he no longer pays attention to your offerings or accepts them with pleasure from your hands. You ask, "Why?" It is because the LORD is acting as the witness between you and the wife of your youth, because you have broken faith with her, though she is your partner, the wife of your marriage covenant.Has not the LORD made them one? In flesh and spirit they are his. And why one? Because he was seeking godly offspring. -Malachi 2:13-15
Behold, children are a gift of the LORD,The fruit of the womb is a reward. Like arrows in the hand of a warrior, So are the children of one's youth. How blessed is the man whose quiver is full of them; They will not be ashamed when they speak with their enemies in the gate. -Psalm 127
God created man in His own image, in the image of God He created him; male and female He created them. God blessed them; and God said to them, "Be fruitful and multiply, and fill the earth, and subdue it; and rule over the fish of the sea and over the birds of the sky and over every living thing that moves on the earth." -Genesis 1:27-28
Let your fountain be blessed, and rejoice with the wife of your youth.As a loving deer and a graceful doe, Let her breasts satisfy you at all times; And always be enraptured with her love. -Proverbs 5:18-19