The world will tell you that children are a burden, lots of work, and expensive. Secular Humanism will tell you that having one child is OK, having two children is acceptable but that any more is irresponsible both to society and to the planet. In fact a recent article states that having children is the single largest contributor to green house gas emissions [link] and that the best way to combat global warming is by not having children.
As believers and followers of Jesus, born into the family of God by His blood we are confronted with mixed messages and complex choices as more and newer technologies and advancements in science are available to us. Often we make decisions based on the advice of trusted doctors or take the counsel of Godly friends, or walk in the ways of those around us...never asking or praying if our decisions are in line with God's word.
If you are married and if you are taking birth control and if you are a born again believer there are things you need to know about birth control. You need to make informed, prayerful decisions.
Here is a sermon from Mars Hill Church in Seattle where pastor Mark addresses this question in great detail.