Children are indeed a blessing, and they are one of the Lord's purposes for creation. God made humans in two sexes, designed to complement one another, to image his glory, and by reproduction to fill the Earth with that glory. Amid the sexual chaos of our society, Christians need to be faithful to God's purposes for us as sexual beings created in his image.
The Bible also teaches that our sexuality can be properly fulfilled only in the secure garden of delights we call marriage (though sin disturbs it). Outside the bounds of marriage, sex is like luscious fruit that God has said is not for us—it does damage instead of good. Biblical commands against sex outside of marriage and divorce are designed to protect not only adults but also the next generation, the children who need a secure world of committed love and affection.
For Jesus, marriage is rooted in God's purposes at the Creation. The other side of the coin is that Jesus calls divorce and remarriage adultery, because it goes against God's created order for the male and female (Matt. 19:1-12; Mk. 10:1-12).
Following this teaching on marriage, Jesus blessed the children and warned adults not to stand in the way of the children coming to him. The implication is clear: Divorce and adultery create obstacles ...