Many courses like Dale Carnegie teach students how to speak well in public. They know that effective communication is a key to persuasion and success in every effort. Even though he’s worried with the correct teaching of the gospel within the church, Paul makes it a point to speak about the mission to proclaim the gospel to those outside of Christ:
Let your speech always be gracious, seasoned with salt, so that you may know how you should answer everyone.
Colossians 4:6 NET
Verses 2-6 deal with evangelism. Evangelism is not mere example in life. If it were, nobody would understand the message. Evangelism is speaking, and speaking well, about Christ.
We all need training in speaking. How to speak more persuasively, more effectively? Christian training happens in practice, daily, in the effort to constantly improve and to never leave off speaking a word and answering inquirers.