Romans 15:1-13

v1-4: What is written in the Old Testament (and now the New Testament too) was written to to teach us.  "Many things are to be learned from the Scriptures, and the learning that is the best is what is drawn from these fountains. Those who are mighty in the Scriptures are the most learned. We must seek, therefore, not only to understand the literal meaning of Scripture but also to apply it to ourselves so that it will do us good."

v5-6: Paul prays for unity in the church so that God is glorified.  When we pray, we should seek God's glory as "our first request... as the foundation of all the others."

v7-12: "No greater joy can come to any people than the coming of the Gospel among them in power." When it comes in power it changes people's hearts, so they want to praise God and it provides lots of reasons for them to do so.

v13: The prayer is directed to the God as the God of hope. "It is good in prayer to focus on those names, titles, and attributes of God that are most suitable to the mission we come on and that will best serve to encourage our faith in it."