In our witness for Jesus are our lives important? Of course they are, we would agree. If the gospel is the power of God for the salvation of everyone who believes, it's salvation from what? Basically from sin and its results. Although the unfolding of that can take a lifetime, and is not really completed until the resurrection when the new creation in Jesus is complete in the new heaven and new earth. And this is not just for us as individuals but for all of creation.
It's interesting that those who spoke the word of God to God's people (in the Old Testament) were called men of God. They were supposed to live out their message, and sometimes with explicit directions, as in the cases of Isaiah, Jeremiah and Ezekiel.
I get a sense of God's salvation working in my life nearly everyday. If I don't, I think I'm in trouble. Why? Because I need it everyday. Salvation in the New Testament is set in past, present and future tenses. But mostly present tense. Salvation is God's ongoing work for us in Jesus by the Spirit. It is communal in that God's people are in it together; it's not supposed to be just a "God and I" endeavor. And it's missional, meant to replicate itself in showing to the world the power of God for salvation in our own lives so that others can find this salvation themselves.
This does mean that people need to see that we are real, and that the Jesus we proclaim to them is real as well. And because salvation is present tense (as well as past and future) we can have a fresh sense of both our need and of God's saving work in our own lives daily, as we trust in God and in his word to us in Jesus.
What would you like to add to these thoughts?