This chapter beautifully illustrates the differences between those who have received the kindnes and love of God and those who haven't. The love of God comes with transforming power. The moral lives of those who believe the gospel has dramatically changed from what they used to be and from what people live like outside the community of faith.
The constant siren song of arguments, empty talk and religious speculation has shipwrecked many a christian and ruined many a church. He comes back to this sooooo many times!
The emphasis on good works again is unmistakable. Christians must be leaders in good works. The outcome of a life of faith matter, not merely what people claim to believe. Christianity is not privately held belief. It is a changed life that produces a good life. The Cretans are lazy gluttons (Titus 1:12). The hard work advocated here would make a Christian very obvious in that context.