David F. Wells, in "No PLace for Truth, or, Whatever Happened to Evangelical Theology?" had the following to say about testimonies:

"Evangelicals have always insisted that Christ is a person who can and should be known personally; he is not simply an item on a creed to which assent should be given. But from this point they have drawn conclusions that become increasingly injurious. They have proceeded to seek assurance of faith not in terms of objective truthfulness of the biblical teaching but in terms of the efficiacy of its subjective experience. Testimonies have become indispensable items in the evangelical fare. Testifying to having experienced Christ personally is peculiarly seductive in the modern context, because it opens up to view an inner experience that responds to the hunger of the 'other-directed' individual but often sacrifices its objective truth value in doing so. The question it poses to the outsider is not whether Christ is objectively real but simply whether the experience is appealing, whether it seems to have worked, whether having it will bring one inside the group and give one connections to others.

"In any genuine knowledge of God, there is an experience of His grace and power, informed by the written Scriptures, mediated by the Holy Spirit, and based upon the work of Christ on the cross. What is not so clear from the New Testement is that the experience should itself become the source of our knowledge to others. To be sure, there was plenty of witnessing that went on in the early church, but it is anything but clear that this should be understood as the use of personal autobiography to persuade other that they should commit themselves to Christ. New Testament witness was witness to the objective truth of Christian faith, truth that had been experienced; our witness today is witness to our own faith, and in affirming its validity we may become less interested in its truthfulness that (sic) in the fact that is seems to work."

(p. 172-173)

I was up at a youth retreat at the camp that I work at a few weeks ago. We had four sessions with the speaker throughout the weekend. His first session was on the horrendous problem of sin. The next session was on the solution: Christ's substitutionary atonement. The third session was on our response to the gospel: "Take up your cross and follow me..."

For the last session, he shared his testimony. It was awesome. Besides the fact that his testimony was awesome, the whole focus was right. It was basically "This is Truth, and because it is truth, I had this experience," rather then the typical "This is my experience, and because I had a good experience, this is truth."

It's quite late, so I'm probably not elucidating this as well as I'd like to, but in that context his testimony was a beautiful thing. I've seen far to much of the opposite in my life.

(Latin phrase goes here.)