The first chapter of Romans talks about how God made Himself known to everyone through the beautiful things He created. But, unfortunately, it also talks about how some people ignore God and do wrong rather than good things.
The chapter says that God doesn't like it when people do bad things and turn away from Him. But it also says that if people genuinely apologize for what they've done and ask for forgiveness, God will forgive them and welcome them back.
So the message for children is that God made the World and wants us to do good things and be kind to others. But if we make mistakes and do something wrong, we can always ask God for forgiveness, and He will forgive us. So we don't need to be afraid of God, but we should always try to do what is right and good.