Today I was in a church, not a bible believing church listening to the class talking about their personal testimonies or really what it is, now they started with a scripture from 2 Corinthians 3:3 "Forasmuch as ye are manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart."
Now at first glance, it could mean something about personal testimonies IF you take this out of context, twist and bend it towards this but look, this verse is NOT about your testimony.
At the beginning of the chapter, Paul is talking about when he begun this church at Corinth, he is saying that he is the apostle that Jesus used to achieve this, and required no letter of recommendation from anyone. Remember, in earlier chapters the Corinthians were saying, "I am of Cephas, and I am of Paul" these people were immature so they were saying shows us your papers, your certificates of merit per se.
Paul is saying here in verses 1-2 that you yourselves are our letter, written on our hearts, known and read by everyone”
Verses 3-4 is basically saying that the people themselves served as authenticating proof that Paul was an apostle of Christ: “You show that you are a letter from Christ, the result of our ministry, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts. Such confidence we have through Christ before God”
Then Paul explains in verses 5-6 that God is the real source of his authority. Paul says "not that we are competent in ourselves to claim anything for ourselves, but our competence comes from God. He has made us competent as ministers of a new covenant; not of the letter, but of the spirit: for the letter kills, but the spirit gives life".
After these verses, Paul begins to contrast the new covenant to the old covenant if you continue reading.
This is sound exegesis and the proper interpretation of scripture.