1. Watch out for those who cause divisions (17-24)
As Paul's conclusion to his letter, he warned the Roman Christians against those who might cause divisions in the church. There were false teachers and troublemakers in the church at Rome that could cause people to act or believe in things contrary to what they were taught. Paul told them plainly, "Stay away from them." Paul commended the church for its obedience to the gospel, but wanted them to also be wise about what is good and innocent about what is evil. Paul was certain that Satan would soon be crushed by God. But they should still be careful.
2. Final doxology (25-27)
These last three verses are Paul's praise to God for the gospel, which is the mystery of God, given to us to bring us salvation from our sins and to give us eternal life. The gospel of Jesus was a revelation in the Old Testament as God's mystery. But in Jesus Christ, it was all made clear. God did this so that "all nations might believe and obey him." (26)