Many Psalms speak of telling others how great God is. Psalm 105:2 is an example, “…tell of all His wonderful acts . . .” Also, Acts 1:8 says, "And you shall receive power when the Holy Spirit comes upon you, and you will be my witnesses . . . to the uttermost parts of the earth." Witnessing to the Messiah’s excellence comes from Spirit-led and Christ-centered words of testifying, as well as Christ-centered actions. Many people who talk to others about the Lord would say that there is a fear and reluctance to speak up and testify, but that the Holy Spirit takes over their minds, hearts and lips, and moves the one sharing to overcome his or her fears and speak up for Christ. It may end up that the person spoken to about the things of God appreciates it and respects the evangelist rather than antagonizing and disrespecting him. It may be a trick of evil spiritual forces to make potential evangelists believe that talking to others will be worse than it actually ends up being, and so they are afraid to speak up. In either case, the goal may simply be that a Christian be so excited about the good news of forgiveness and justification in the Lord that a person can't help but share and talk to others about it.
Testifying about the Messiah can simply be a person sharing what his spiritual eyes see the Messiah doing in and through him. An example is, “I didn’t feel like being loving in a certain case, but the Holy Spirit took over my thoughts and actions and I was loving anyway. With my spiritual eyes, I saw this happen inside me.” So outreach can and does involve testifying to what a person’s spiritual eyes see God do in them. It can involve many other things, but it can involve this.