7.  TO DEFEND US, HELP US, AND PROTECT US.

Psalm 127:5 tells us that the man who has his quiver full of arrows will never be defeated when he meets his enemies in the place of judgment. He will have children who will stand up for him and fight for him.

8.  TO CARE FOR US WHEN WE ARE OLDER.

Read Proverbs 23:22; Isaiah 58:7,Matthew 15:4-8; Mark 7:9-13; John 19:25-27; 1 Timothy 5:3,4,8,16. As you can see, there are many scriptures about this subject. God's plan is that the younger generation will care for the older generation. This also affects the whole nation. If we do not have the children God has destined for us to have, there will be an imbalance in the population - there will be more older people than younger. 

7. FOR GOD HIMSELF.

This is the highest reason. Although God gives us the joy of children for the above reasons, they are really His children. When God spoke to His people about their children, He called them "MY children...", "the sons and daughters whom you have borne unto ME." (Ezekiel 16:20,21). We do not have children, just for ourselves and our own benefit, but for God!  We nurture them and train them for Him.

Parenting is the highest calling God has given to mankind. Every other career is subservient to this one. Everything else we do in life serves our highest calling of teaching and training the next generation for God. Finis Jennings Dake, in the 'Dake's Annotated Reference Bible' comments on Psalm 127:

"Each child will in the process of time be a defense, support and propagation of the eternal reproduction of man and fulfillment of the plan of God for man. The more arrows one has, the more enemies he will slay, the more powerful will he be in the earth. The more children born and saved to help God administer the affairs of the eternal plan for man, the more reward God will have."