Making the world a better place can be a joyful enterprize, that is, if we do it God's way as God instructed in Genesis 1:28.
God blessed them; and God said to them, “Be fruitful and multiply, and fill the earth, and subdue it; and rule over the fish of the sea and over the birds of the sky and over every living thing that moves on the earth.” (NASB)
Part 1: Be fruitful - Join together, male and female, in marraige and out of love bring new life into your home. See children as a blessing, not a liability. They will indeed change your life and for the unimagingable better as you train them in the Lord.
Part 2: Subdue - Align your life, your family, your church, and your society with God's created designed order and ways, caring and utilizing all of creation for the good it was designed to deliver, that all creation may shine with glory to its Creator.
At the family level, train your children in the ways of the Lord, so they will know the way to live by truth and have abundant life. (Duet. 6:4-7, Prov. 22:6)
The Christian, who by definition embraces Jesus, who is the way, the truth and the life (John 14:6) must not give their children to the lost to be descipled by the lies of the culture of death. Not only will that steer a child down a path that leads to ruin (Psalm 1, Mark 9:42), it also sustains/feeds the culture of death. Instead, let the culture of death collapse under its own lies that oppose God's design of procreation and families. That is how to make the world a better place! One family at a time! Build yours on the Solid Rock.
State entitilments have created a mindset that has done more harm to the institution of the family, incuding multi-generational family, than even abortion and other immoral sexual choices. State entitlements essentially obsoleted the family. Trust God's design. Parents take responsibility for training up children and later trained children take responsibility for aged parents.
Godly societys are built from Godly families. Godly families are built from Godly individuals. Be fruitful and subdue!