“This is what is written: The Christ will suffer and rise from the dead on the third day, and repentance and forgiveness of sins will be preached in his name to all nations, beginning at Jerusalem. You are witnesses to these things.”
Jesus tells his disciples to be witnesses to the truth of what has happened. While nothing we say can confirm or detract from the Word of God, we do bear witness to its trustworthiness.
The challenge in this is to live our lives in a manner that allows others to see us as trustworthy so that what we share about Jesus is also trustworthy. Difficult? Yes. Challenging? Yes. Worth the effort? Absolutely.