The Christian's decision goes much deeper than merely having the money, coping skills, or space to raise a family. With both our incomes, there's still no way we could support a child. Married couples should be able to use birth control if they choose. God gives wisdom and knowledge to doctors. We should take advantage of the medical resources God's provided us.
Birth control is a way of sensibly managing the ability to multiply.
For years I practiced birth control and thought nothing of it. Then the Lord showed me, through Scripture and prayer, that I'm not my own. I belong, body and soul, to my Savior Jesus Christ. When my husband and I first considered birth control options, we learned that some forms of birth control occasionally disrupt implantation of the fertilized egg, effectively causing an abortion. So we opted for Natural Family Planning, which cooperates with the way God made us.