Memorize this!
The most important verses Paul wrote are Romans 1:16-17. Here they are:
For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. For in it the righteousness of God is revealed from faith for faith, as it is written, the righteous shall live by faith.
They are the guts of the book. If you understand those two verses, you understand everything Paul has ever written. That's why when I teach my daughters to memorize Romans, it doesn't really bother me too much if they only memorize a small part of it. It doesn't really bother me too much if they forget everything else. But if they can at least file these two verses away before their sixth birthdays, they will know enough to be right with God.
Once they understand that the Christian life begins and ends with trusting God's righteous promises, they are, as we say in Sydney, laughing.