In verses 15 and 16 Paul's lists both proper and improper motives. They were envious about the way the Praetorian Guard responded to Paul. Love is an advance on good will. Wolf packs turn on their own when one falls in the fray.
Christians often shoot their wounded as well.
Preaching without love is just a lot of noise. Preaching like that is just sound and fury but without integrity. Paul saw his purpose as defending the gospel. He knew his mission. He saw himself clearly in God's plan of world evangelism.