Wilkerson points out that many of these churches are megachurches that nearly spring up overnight.
The church at Jerusalem could be termed a "megachurch" because thousands of Jews were save at Pentecost and shortly thereafter. But this was a supernatural work of the Holy Spirit, and "the apostles doctrine" was being taught.
Today's megachurches, by definition, have compromised many biblical truths and principles, including the true Gospel. And there is no question that in order to gather large numbers together, many ears must be tickled.
What the leaders of these churches forget is that it is an extremely serious matter to tamper with God's truth and His pure Gospel. There will be grave consequences. So they need to give heed to what Paul has said:
For we are not as many, which corrupt the word of God: but as of sincerity, but as of God, in the sight of God speak we in Christ... Therefore seeing we have this ministry, as we have received mercy, we faint not; But have renounced the hidden things of dishonesty, not walking in craftiness, nor handling the word of God deceitfully; but by manifestation of the truth commending ourselves to every man's conscience in the sight of God.
But if our gospel be hid, it is hid to them that are lost: In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them. For we preach not ourselves, but Christ Jesus the Lord; and ourselves your servants for Jesus' sake. (2 Cor 2:17; 4:1-5)