Paul might have been responding to the Corinthians who were constantly asking where he got his authority to teach and how he received the message he taught, but I think his words tell us a great deal about ourselves, as well. Each of us is commissioned by God to be messengers of the gospel - the good news about Jesus Christ. None of us is exempt from this mission. If this is true, then we all need to be certain of where it is we have received our authority to share this truth and exactly what truth it is we are going to share. The best way to avoid believing a lie is to know the truth so well that you cannot be duped into believing the lie - you will be able to spot the portion which isn't true. If we are to become adept at sharing the message we have received of God's grace and mercy extended to all mankind, then we need to understand the truth of this message both personally and for those who need to receive the liberty it brings to their lives, as well.
Don’t be mistaken; in and of ourselves we know we have little to offer, but any competence or value we have comes from God. Now God has equipped us to be capable servants of the new covenant, not by authority of the written law which only brings death, but by the Spirit who brings life. (2 Corinthians 3:5-6 VOICE)
In and of ourselves, we have very little to offer - although educated, we don't walk in the full truth we possess. Isn't it so like us to think we can possess truth, but then not have that truth become the means by which we make decisions, take actions, and see outcomes in our lives? We often possess much more than we use in the natural sense. Our pantries are stocked - not because we need to use every canned item this week in preparing our meals, but because we stocked up when their was a good sale on spaghetti sauce! We have a tendency to "possess much", but use very little of what we possess. The average American purchases homes bigger than what they need - not because they plan to have larger families, but because it is the thing we Americans do. We somehow equate bigger with better and in so doing, we often over-extend ourselves in ways which impact us financially, in relationships, and emotionally.
Truth isn't something we possess, but something we embrace and allow to impact the way we live. I think this is what Paul is telling the Corinthian church. He isn't going to argue with them about who or what gave him the authority to bring them the good news about Jesus Christ. He isn't going to tout his credentials as a well-schooled scholar of truth. He is merely going to allow his life to speak for itself and the outcome of his teaching in the lives of those he touches with his life to speak even louder. This is something we can learn from Paul - our lives may speak volumes, but the lives we impact when we share the truth we embrace speak even louder and with even more clarity. It is like truth "echoes" in the lives of those who receive it - until the truth we embrace becomes the truth by which others are embraced, as well.
We are equipped to be "capable servants". One who is considered "capable" has the capacity to do something - they are considered "competent" in their actions. All equipping of our lives comes not in the pursuit of scholarly things, but in allowing God to take truth and make it the basis by which we live and breathe. I attended Bible School and graduated with honors. Yet, I didn't gain any "credentials" because of my schooling. My "credentials" - the things which make me a "capable servant" of the gospel message come directly from God himself working out that gospel message within me day-by-day. The same is true of each of us - it is in the living out of the truth that truth becomes alive and reproducible in others.
It is the Spirit of God within us who makes truth alive - first to us, then to those who are touched by our lives. No truth is meant to be exclusive to the one who receives it - others need the truth God has worked out in your life as much as you do. To think we possess some truth others cannot or do not possess is where we get into the pathway to false religion and cult-like activity. Remember this - God is the one who makes us "capable servants", each receiving truth in fullness, not in measured portions. We may receive "revelation" of truth at differing times - like when we understand what it is to fully trust in God's provision after losing a job, or how dependent we are on him for our health in the face of receiving a bad diagnosis from a doctor. As we face life events, we press in to get more from the truth we possess - and in turn, we are called to share what we come to experience in those times of "pressing".
No authority is given by man to share the truth of the gospel of Jesus. If this is true, and I believe it is, then we all have the "authority" to preach the gospel - not just those schooled in the Word at theological institutes! We do much more in "preaching" the truth in how we "live it out" every day than we will ever do by taking to the pulpit! Just sayin!