This mindset of "no judging" is one of the most dangerous, Gospel undermining falsehoods around. If it were even remotely true we would have a much smaller New Testament. While that would make "Bible in a year" reading plans easier to complete, this philosophy is anti-Biblical and anti-Gospel. Peter, Paul and the other apostles didn't go around telling people "God loves you just the way you are. Heck we are just sinners too! Come to church on Sunday." They called out sin and called on people to repent, relying on the regenerating power of the Holy Spirit to change hearts and create born-again new creations.
Sexual behavior is one of the most powerful impulses in humanity. It is at the same time one of the most wonderful gifts we are giving within marriage, especially when it results in the blessing of children, but it is also, not coincidentally, perhaps the most twisted and abused impulses among humankind. The Bible is full of examples of this, from the destruction of Sodom and Gomorrah followed by the incest between Lot and his daughtes to the rape of Tamar by her brother Amnon. Humanity bears this out all through history and every day still. It seems that there is no end to the human appetite to pervert God's design for sexuality in His image bearers and there is no counter to that insatiable appetite except the life shattering Gospel.
Where we run into trouble on this "judge ye not" idea is in application. Ought we judge unbelievers and believers alike, or not judge them alike as the case may be? Absolutely not. The only way to come to that conclusion is willfully ignoring the Scriptures in favor of the whims of contemporary culture.. Paul gives us a critical glimpse into how the church must deal with sin, especially sexual sin, in our midst in his first letter to the church in Corinth.
It is actually reported that there is sexual immorality among you, and of a kind that is not tolerated even among pagans, for a man has his father's wife. And you are arrogant! Ought you not rather to mourn? Let him who has done this be removed from among you. For though absent in body, I am present in spirit; and as if present, I have already pronounced judgment on the one who did such a thing. When you are assembled in the name of the Lord Jesus and my spirit is present, with the power of our Lord Jesus, you are to deliver this man to Satan for the destruction of the flesh, so that his spirit may be saved in the day of the Lord. Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth. I wrote to you in my letter not to associate with sexually immoral people—not at all meaning the sexually immoral of this world, or the greedy and swindlers, or idolaters, since then you would need to go out of the world. But now I am writing to you not to associate with anyone who bears the name of brother if he is guilty of sexual immorality or greed, or is an idolater, reviler, drunkard, or swindler—not even to eat with such a one. For what have I to do with judging outsiders? Is it not those inside the church whom you are to judge? God judges those outside. "Purge the evil person from among you." (1 Corinthians 5:1-13)
Human sexuality is designed only for enjoyment within the boundaries of heterosexual, monogamous marriage. That is incontestable from Scripture. We can look all the way back to the beginning to see the genesis (pun intended) of this vitally important human relationship:
The man gave names to all livestock and to the birds of the heavens and to every beast of the field. But for Adam there was not found a helper fit for him. So the LORD God caused a deep sleep to fall upon the man, and while he slept took one of his ribs and closed up its place with flesh. And the rib that the LORD God had taken from the man he made into a woman and brought her to the man. Then the man said, "This at last is bone of my bones and flesh of my flesh; she shall be called Woman, because she was taken out of Man." Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. (Genesis 2:20-24, emphasis mine)
Many people point an accusing finger back at the church for failing to show the same fervency toward other sinful behavior like divorce, adultery, greed, gossip, etc. that we exhibit toward sexual sins It is absolutely true that we are far too quiet in many areas of sin in the church. The real question is what do we do about it? One "solution" is to be equally silent about sexual sins, if we aren't going to be consistent we should just shut up. The other is to redouble our discernment toward all sins in the church, not just the ones that are easy to point out like homosexuality. Failing in some areas is not a license to chuck the whole thing and replace it with an "anything goes" religion that guts the Gospel in favor of a happy clappy attitude that not only refuses to call sin what it is but embraces and celebrates it.
Biblical love is not our contemporary sappy notion of "love". Biblical love is not blind and it is not mute. Biblical love sees when one who bears the name of brother is sinning and speaks the truth in love in the hope of renewal and restoration. We do sinners no favors and are not their friends when we turn a blind eye and shut our mouths to allow sinners to be content in their sins. No one will thank us for our blindness and voicelessness when they stand before the Judge.