Not only the world, but we also have been waiting with pain inside us. We have the Spirit F67 as the first part of God's promise. So we are waiting for God to finish making us his own children. I mean we are waiting for our bodies to be made free.
We were saved, and we have this hope. If we can see what we are waiting for, then that is not really hope. People don't hope for something they already have.
Also, the Spirit F68 helps us. We are very weak, but the Spirit helps us with our weakness. We don't know how to pray like we should. But the Spirit himself speaks to God for us. The Spirit begs God for us. The Spirit speaks to God with deep feelings that words cannot explain.
God can see what is in people's hearts. And God knows what is in the mind of the Spirit, because the Spirit speaks to God for his people in the way that God wants.
God knew those people before he made the world. And God decided that those people would be like his Son (Jesus). Then Jesus would be the firstborn F69 of many brothers and sisters.