He’s saying to show himself as an example in everything—in good deeds, in uncorrupt doctrine, in gravity, sincerity and sound speech.  So that those that would oppose or contradict him would not be able to say anything evil about him (People can always say evil things about you, but they won’t be able to truthfully say anything evil).

The only way anyone can do this is to not only have a strong foundation of the Word of God in their life and also to be sensitive to the Holy Spirit within.  The Holy Spirit is our Helper and we’re told to be filled (or stay filled) with the Spirit (Ephesians 5:18).

Thank God the Word of God and the Spirit of God agree with each other so we can know the Truth in our hearts and be assured of the Truth so we can confidently walk in it.  That’s the only way we can be confident about our beliefs and our teachings and as a result be a doer of them.  Without the Word of God and Spirit of God agreeing we could more easily get off into error and not be as bold and confident about the Truth of the Word.

By filling our hearts with the Word of God and by being filled with the Spirit of God the two bear witness to each other and as a result we become bold and confident concerning the Truth of God’s Word and have the strength and ability to do and speak what is right!