I'm all for people having the number of children they believe God has for them. If a couple wants to have lots of kids, like the Duggars, that's a wonderful thing. Children are clearly a blessing from the Lord.
Psalm 127:3-5 tells us, "Behold, children are a heritage from the Lord, the fruit of the womb a reward. Like arrows in the hand of a warrior are the children of one's youth. Blessed is the man who fills his quiver with them! He shall not be put to shame when he speaks with his enemies in the gate."
That said, I do not believe that the number of children a couple has is of importance. Some may choose to have two, some three, some four, etc. God instructed both Adam and Noah to be fruitful and multiply. However, God did not specify number. We also must be careful whenever we take narrative commands and apply them to ourselves. For example, no one expects us to build an ark.
I do believe it is problematic if a couple chooses to have no children whatsoever simply because they want the freedom from raising others. This is selfish beyond measure. After all, someone took the time to raise them.
Some couples may elect not to have their own children, but instead to adopt. This is beautiful. Other couples will have their own and adopt. I applaud.
Additionally, other couples may not be able to have any children due to a variety of physical issues. I'm clearly not referring to them when writing about those who choose to have no children for freedom's sake. My hope is that every Christian couple who cannot have kids will be able to adopt.
I write all this to say that we in Christ should not fight over this issue. Satan would like nothing better than to cause strife within the church regarding number of kids. At worst it causes fighting, and at best it is a distraction.
Let's all just take joy in the kids we have and that God may give to us. No one is a better Christian because he or she has a different number of children than anyone else. It's not an issue worth fighting over.
As Christ's church, we must stay focused on the task at hand: making disciples. Let's avoid distracting arguments like this one at all costs.