Qf
Our family is "quiverfull" - meaning that we have given over control of our fertility and family size to God. We find this is a way to be honoring to God since He is the one who we believe has created all things and knits babies together - so we believe any children He gives us is "planned" (by Him as part of our family) and that children are a gift from the Lord and a heritage - "children are like arrows - blessed is the man whose quiver is full of them". We also believe it just doesn't make sense to us to "reject" blessings - most people usually ask for blessings in their life.
Uh - ya I not only talk in church but am on the worship team singing in front of thousands of people on Sundays

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I could describe having many children as building an army - but not to have more Christians than non-Christians. As a Christian I do not believe our battle is against people but powers of darkness (demons, Satan). Our "army" weather it's two children, ten or twenty - would be one that shows the attributes of our God to others -love, healing, strength. We believe God designed the family so we want to raise our children to cherish their spouse and children as well. It's not to "over populate" - it's to continue our heritage - to pass it down to the next generation and encourage them to do the same.
There is also a command God gave after creating the first man and woman as well as after the Biblical flood of Noah - to Noah and his family to "be fruitful and multiply and populate the Earth". Some Christians believe God would still want people to continue "multiply" by having "x amount" or "as many as you can have". Others believe that command was just for them to get mankind started. Since there was never a command to the contrary some assume it is still in effect. So - we leave it up to God - we figure if He wants the Earth more populated (or at least our family more populated) then He'll continue to bless us with children.