Titus 3:1-7 describes how believers at to glorify God in an ungodly world. We are to be submissive to the government and kind to all men (1-2). Verses 3-7 answer the question of why?
Titus 3:3-7 answers this question - Why should I treat unbelievers in the way verses 1-2 describe? Paul gives us two Gospel realities to remember:
Remember that you were just like them (3) - They are sinners
Remember that you are saved by grace (4-7) - They need the Gospel