I have one other introductory thought. There is a special need to consider the divinely inspired words of Matthew 10:41 & 2 John 8-11 as a needed correction to the common thinking of today's church. Though admittedly it's not stated explicitly, one could easily conclude the church considers herself more Christlike in its treatment of the surrounding culture by the way she doesn't intentionally rebuke its sin.
We will only appear judgmental and self-righteous if we're perceived as being against what is ungodly. Certainly we'll gain more ground for the kingdom if, instead of being judgmental, we simply embrace and show the love of Jesus. After all, He dined with publicans and sinners. And He even said He didn't come to condemn the world. So we will appear more winsome and more Christlike if we don't come across as being against a whole bunch of people we're trying to reach. It all just seems to make sense.
But perhaps this is going too quickly. The real issue, of course, is what kind of love is the church to show the lost? Is holiness - without which, apparently, no one will even "see the Lord"(Heb.12:14) - is this holiness just something to be pursued or also proclaimed? Is the doctor life-loving toward his patient when he takes his cancer-ridden patient out for dinner or when he prescribes live-saving radiation?
I know there are shades of truth here. I cant reach anyone in any way unless I establish some friendly relationship. It's almost impossible to make any hard truth reach a total stranger. We can't place ourselves on some other planet and reach the lost. That much is for sure. But that's not the point John's trying to make in today's text. John means to remind our church that at some point in any contact with our culture two worlds will have to collide. There is no avoiding this. Nothing has changed since the Light first shone in the darkness and the darkness hated the Light. The issue of today's text isn't the obvious need of making contact with our culture. The issue is what kind of contact must we make. The issue is what is a Scripturally loving response to our culture's participation in eternally damming sin.