They have never been taught the truths of John 15. Abiding in Christ is simply plugging into Jesus. Its relying upon Him to do your work for God. God doesn't need your intellectuality or your popularity amongst people. His word teaches that He uses the foolish things to confound the wise.
Churches dry up and blow away when they fail to learn how to plug into Jesus.
We gather together and sing choruses of praise. But some stand there and talk to each other while the rest of the people praise Jesus. You not only interfere with the moving of the Spirit of God when you do that, but you are not plugging into Jesus so that when the sermon is preached to you, you can receive everything that it offers for your Christian life and spiritual maturity. Reach out and mean every word that you sing when you sing choruses of praise. Reading words from a hymn book and not meaning one word that you sing is as bad as reading prayers from a prayer book.