It's a fairly common (and typical) human pastime to categorize, divide, discern and separate people. Pondering this, I conclude this is part of the "survival mechanism" of the carnal mind. The unknown is potentially dangerous and thus our instinct is to turn the unknown into the known by slapping a label onto it. Then we have the illusion of safety in the familiarity of the thing. Unfortunately, the only way we know to do this is to put the thing into an already known category based on similarity of appearance, filtering out what doesn't fit. And so it goes.
Ah, but we know that appearances can be deceiving and our constant attempts at categorization tend to mislead. So, what "appearances" SHOULD we take into account?
"Watch out for false prophets, who come to you in sheep's clothing but inwardly are voracious wolves. You will recognize them by their fruit. Grapes are not gathered from thorns or figs from thistles, are they? In the same way, every good tree bears good fruit, but the bad tree bears bad fruit. A good tree is not able to bear bad fruit, nor a bad tree to bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. So then, you will recognize them by their fruit. (Mat 7:15-20)
Well, there you go. Hmmm. I have a question... What is the "good fruit" that identifies the good tree? To hear most people talk about it, usually they consider "good fruit" to mean: "You are like me." Yes, indeed, the ol' ego gets right in there and starts to work. If I am OK, then to be OK, you must be like.... ME! Religion usually works that way. If you do OUR rituals, wear the same clothes we do, etc. then you are one of US and must be one of "God's special chosen ones." HAH HAH. I don't think that's what Jesus is talking about here.
Here's the conundrum as I see it. We tend to think in "existentialist" terms - that you are what you do - and the comments of Jesus appear to confirm that. But, reading more carefully, the opposite is truly what He meant - you do what you are. In order to bear good fruit, your nature must be that of the good tree. So, we can't and MUST not just look at the outward appearance. But the projected appearance is the only thing we really CAN see! Yikes. To know "good fruit" means we need a benchmark that is a valid and correct one to compare against - one that truly represents the inner being not just the outward appearance. Well, here it is:
But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control. Against such things there is no law. Now those who belong to Christ have crucified the flesh with its passions and desires. If we live by the Spirit, let us also behave in accordance with the Spirit. Let us not become conceited, provoking one another, being jealous of one another. (Gal 5:22-26)
So, now we know. All we need to do is change the inner nature to one of love, joy, peace, patience, kindness, goodness, and self-control and then we can bear fruit. And if we find someone who lacks self-control, love, peace and patience, we know that the actions of that person are not guided by the spirit. Likewise, if our own actions are not based on self-denial out of love for others, we know we need an inner change as well, so that we will produce the good fruit of the Spirit of Christ.
How ya gonna do that? How can an impatient person become patient? How can an insecure person become secure? How can a person without self-control control the self? Can't be done. Except, we have this promise:
Remain in me, and I will remain in you. Just as the branch cannot bear fruit by itself, unless it remains in the vine, so neither can you unless you remain in me. "I am the vine; you are the branches. The one who remains in me and I in him bears much fruit, because apart from me you can accomplish nothing. (Joh 15:4-5)
So there it is. To "remain in Christ" is just another way of saying "Have Faith in Jesus." He will change YOU when YOU no longer try to put on "good fruit" but only seek to put aside the ME so that the HIM can go to work. Not so hard to understand; a little difficult to do. It takes lots of practice.
It solves the problem of categorizing others, and leads to the correct understanding of what Jesus is talking about in Matthew 7. His words must be taken in the larger context of "Judge not lest you be judged." (Matt. 7:1) We don't really need to have a "survival mechanism" that forces us to judge, condemn, categorize, limit and dismiss others. The self no longer needs to be protected and preserved since it remains in Christ. I don't need the others to tell me WHAT to do since the Christ in me tells me that. I don't need to tell others what to do either, only show them the Spirit of Christ working in me. Having that Spirit in me, I can now recognize it, or the lack of it, in others. And knowing through experience that the Spirit of Christ leads to self-denial I now have a valid benchmark. Where there is self-preserving condemnation, I know it is not the Spirit of Christ.
That does not give me the right to condemn in return, as to do so is to split myself from Christ. In the original context, the "cut down and throwing into the fire" is something that will be done by God when it is His time to do so. I don't have to worry about that. To know the false-prophets is not for the purpose of condemnation, only that we do not be drawn away from Jesus into some man-made solution. I remain in Him; He remains in me. I am not threatened by them, since my well-being is not dependent on them. Thus I don't need to condemn, but only to love those who need love.