And now for the third installment on handling your neighbor - Give your neighbor time to grow.
Now, here I am going to touch upon growth. Here is a simple fact - people grow. We grow in wisdom, we grow in experience, etc. Now, I'm not going to go off on a progressive sanctification bent or a bunch of finger wagging about how you should be growing. I think my favorite observation I've ever made in a sermon is that you don't make the cluster of grapes grow by walking up to it and shouting "grow! I said you were supposed to be growing, grow faster!"
No, the simple fact is that those who are in Christ, who hear His Word, who receive His gifts will in fact grow. He is the vine, we are the branches, when we abide in Him, fruit will mature and be produced. This is just the way it is. Growth happens.
The problem comes in when we become... impatient with how quickly our neighbor is "growing". Then, instead of letting God give growth as He sees fit, we can want to jump on in and "make" them grow faster. Or we can become frustrated and write them off (because if they were "real" Christians they wouldn't be annoying me so much).
This is all flawed. The image I like for the third use of the Law is that of a trellis - it is something upon which a Christian grows, the branches cling to it as they grow. A trellis is not used properly to beat a plant into upward growth - nor is it used rightly if you rip the trellis (and branch) out of the ground in frustration.
People will not be as mature as you want them to be. That's the simple truth. Give them time to grow.
And if that becomes frustrating - think about you yourself 5 years ago, or 10 years ago, or 20. Now, hold that past you up to the standards you are applying to your neighbor. If you think you stand... just keep going back and back further into the past until you see, "ah, back then I was worse." Then chill out, and let God give growth to your neighbor as He has given growth to you.
If you never get to a point where "you" failed... well, quit lying to yourself you egotistical jerk and learn some humility before you even think about looking at your neighbor... jerk. Seriously - if you pulled that big old log out of your eye (or maybe its a self-righteous stick that needs to be pulled out of a slightly more creative place) you might learn to abandon that disdain you have for your neighbor.
Be patient with them, as God has been patient with you. Encourage - that is, speak a word of forgiveness to your neighbor often, praise when they do well. Focus them upon Christ again and again and again. And they will grow. It may take time, but God is patient.
Seriously - just remember how patient He's been with you.