"Therefore I write these things being absent, lest being present I should use sharpness, according to the power which the Lord hath given me to edification, and not to destruction." (2 Corinthians 13:10)
Planting a seed
Paul concludes his second letter to the Christians in Corinth with this little outro. Almost a warning, he reminds them that they are receiving a gentle admonition--in writing. In chapter ten (verse 8), he says the same "...our authority, which the Lord hath given us for your edification, and not for your destruction." This gentle reminder that he has the "power" to back up his words is not to be taken lightly. Think of it this way: if all we want to do is hear God speak to us on a matter, we had best be ready to receive it. Because if God showed up and spoke something that you hadn't grown up into in order to receive it, it may well end in fracturing any false structure in which we've filled our days and years believing lies. What I mean is, sometimes, if we would hear the unvarnished truth yet hear it out of the timing of God, it could do more harm than good.
"That I may not seem as if I would terrify you by letters." (2 Corinthians 10:9)
Planting a cede
Here's a pointed example. Say you have a friend with whom you're close. They shore you up even as you in turn do the same. You complement one another and have each been through hell together. James (5:16) says "Confess your faults one to another...that ye may be healed." Which you've done. You seek to live out a godly means of community between yourselves and it works. You might be polar opposites but you both love Jesus and that's more than enough. But here's the thing. Remaining in Christ even after you've parted ways for the week is vitally important. Because the treasures and deep places of the heart with which you commune are down in the same sensitive places (in each) as dwell faults and failings and things not brought to light (yet). And by remaining in the flow of the Holy Spirit even as you're apart, you won't end in saying or doing things with those confidences that result in planting a seed of separation, however slight. Nothing Jesus pointed to in regards to Christian community (however microcosmic) ever had the downside of separation-by-offense.
The solution is this: "and pray for one another". That's what is represented by the ellipsis above and it no more needs to be left out of our interaction than the interaction itself.