Never forget the centrality of the Word of God to the believer's witness. The Christian is to study the Word, apply it to himself and then translate it into daily living before a crooked and perverse world.
And every believer may be assured that as God's Word is held forth it will have an effect on those who hear it.
Hebrews 4:12 says, "For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart" (NASB).
There is no substitute for holding forth God's Word, for if people are to come into right relationship with Jesus Christ, they must know what God's Word says.
Romans 10:17 says, "Faith comes from hearing, and hearing by the word of Christ" (NASB). So if those we witness to are to be able to have faith in Christ, they must have the Word of God presented to them.
We must first benefit from the Word ourselves before we become concerned about passing it on to others. We cannot do the work of God or have the right attitudes (as urged in the previous verses) unless God's Word is doing its work within us.
The Word of God goes to the deepest parts of our nature. It exposes, sifts, analyzes and judges even our thoughts (see Heb. 4:12).
"The law of the Lord is perfect, converting the soul: the testimony of the Lord is sure, making wise the simple" (Ps. 19:7).