Thanks to the "seeker-sensitive" church model and the popularity of the false idea that the Church is a "hospital for the sin-sick," the Church is crowded with false brethren and the lost who bring with them lives full of "leaven," with little interest in leading the crucified life (Matthew 16:24-25; Galatians 2:20; Colossians 3:1-3), the life of holiness and sacrifice, unto which God has called all of His own. Their leaven has leavened the Church powerfully, just as Paul warned it would, so that now believers have taken up the notion that holiness is a pipe-dream, that a life largely free from sin is impossible.
When genuine believers look around their local community of believers, they see at every turn folks who are mired in all sorts of moral compromise. The resulting assumption the genuine believer often makes is that such compromised living is the norm. But what they are seeing in the Church is a degenerated, corrupt version of what is described in Scripture, created by the Church opening itself to the lost and the Satan-governed World and its assorted evil philosophies and values which the lost have embraced.
The Church is to go out into the World and preach the Gospel (Mark 16:15), not crowd itself with the World, with those who neither know nor love God. The Church is supposed to be separate from the World (2 Corinthians 6:14-18; James 4:4; Galatians 6:14; 1 John 2:15), the pure, holy Bride of Christ (Ephesians 5:25-27), shining as a light on a hill (Matthew 5:14-16), piercing the darkness of the World with God's truth, holiness and grace. Instead, the Church has taken in the sin-sick and all their "leaven" and become sin-sick itself, impotent spiritually, a dim and dying light among the lost.
Every genuine disciple of Christ is to be an evangelist, sharing the Gospel with the lost. And when they have brought the lost to a saving faith in Christ and discipled them in the basics of the faith, taking the time to see that the marks of genuine salvation are in evidence in the new believer's life, then they ought to introduce them to their brothers and sisters in Christ, the Church.
But the cult of personality, and the press for a money-making, empire-building, business-style form of Church life, and the idea that only certain paid leaders in the church are to evangelize and disciple, has fostered a version of the Church (at least in the West) where the lost are brought in to the local community of believers to hear the preacher (he's sooo amazing, you know!), and the worship team (never mind that you don't know Christ as your Saviour and Lord and cannot really properly worship Him) and to meet lots of nice people (who will never call you out on the sin that will ultimately destroy you) but never hear of their desperate need of Christ from the person who brought them.
And so, modern, western Christians look at the Bible and see in it a totally different Church from what they know. But, rather than conforming to what the Bible describes, many modern believers edit the Bible instead to make it more "relevant," which is to say, more in line with what they know as the Church: carnal, and Worldly and spiritually dead.
Ephesians 5:1-12
1 Therefore be imitators of God, as beloved children;
2 and walk in love, just as Christ also loved you and gave Himself up for us, an offering and a sacrifice to God as a fragrant aroma.
3 But immorality or any impurity or greed must not even be named among you, as is proper among saints;
4 and there must be no filthiness and silly talk, or coarse jesting, which are not fitting, but rather giving of thanks.
5 For this you know with certainty, that no immoral or impure person or covetous man, who is an idolater, has an inheritance in the kingdom of Christ and God.
6 Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience.
7 Therefore do not be partakers with them;
8 for you were formerly darkness, but now you are Light in the Lord; walk as children of Light
9 (for the fruit of the Light consists in all goodness and righteousness and truth),
10 trying to learn what is pleasing to the Lord.
11 Do not participate in the unfruitful deeds of darkness, but instead even expose them;
12 for it is disgraceful even to speak of the things which are done by them in secret.