Question: "What does it mean that our lives should be a testimony for Jesus?"
Answer: The “testimony for Jesus” in view here would be a lifestyle and words that openly acknowledge our personal experience of following Jesus Christ. A testimony must be public because its purpose is to tell others what has taken place. In the Christian experience, our regeneration should be a testament (evidence) to other people that Jesus is alive and is changing lives. We testify by our words and actions. If our lives are a testimony for Jesus Christ, then they should be reflections of Christ as we “follow in his steps” (1 Peter 2:21).
In Acts 4:33, the apostles give their testimony in words: “And with great power the apostles were giving their testimony to the resurrection of the Lord Jesus.” The apostles, testifying of the resurrection, were telling others what they had seen with their own eyes, heard with their own ears, and touched with their own hands—they gave a personal, eyewitness account of Christ’s resurrection. In the same way, believers today are commanded to tell others of what they have witnessed firsthand. We haven’t had a face-to-face experience with Jesus as the apostles did, but our conversion experience is no less genuine and no less proof of God’s supernatural work in our lives. We should eagerly share with boldness and humility the change that has taken place in our hearts.
Revelation 12:11 says that believers “triumphed over [Satan] by the blood of the Lamb and by the word of their testimony; they did not love their lives so much as to shrink from death.” Notice the “word” of their testimony, meaning these triumphant ones spoke verbally, without shame or fear. Some believe that Christians ought not verbalize their testimony but should simply live it out in their daily lives. But it’s not an either-or proposition. Living the gospel message is important, but it’s no more important than our verbal testimony, since God has chosen “hearing” the Word as the means of producing faith (Romans 10:17; see also John 4:39).
A life dedicated to Christ is a powerful testimony. Paul describes such a life in 2 Corinthians 1:12, “We have conducted ourselves in the world, and especially in our relations with you, with integrity and godly sincerity. We have done so, relying not on worldly wisdom but on God's grace.” When our actions of godly living match the words coming from our lips, our testimony will be seen as true.
In the Beatitudes, Jesus provided a list of those who are blessed: “the poor in spirit . . . those who mourn [over their sin] . . . the meek . . . those who hunger and thirst for righteousness . . . the merciful . . . the pure in heart . . . the peacemakers” (Matthew 5:3–9). Jesus summed up a godly life with two commands: “‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ This is the first and greatest commandment. And the second is like it: ‘Love your neighbor as yourself’” (Matthew 22:37–38). A Christian who wants to live his life as a testimony for Jesus will love God above all else and love others above himself. When a believer shares what Jesus has done in his life and serves God and others in tangible ways, he will increasingly reflect the life-giving power of Christ into a dark and dismal world.