I know the western church has many idols, but I am frequently confronted by one which seems to be too easily and uncritically erected where Jesus belongs. That is the idol of church growth. When the bottom line of your church is growth, when your church exists primarily to grow (whether that is through church planting, multiple congregations, multi campuses or multiple services or just a really big auditorium) then it is inevitable that eventually you will find yourself doing what works to promote growth rather than what God is really asking you to do, and by that stage you wont even realise it.
Does the Body of Christ need to go on a diet?
The bottom line of any Christian church should be faithfulness to Jesus. Pastors and the people they lead need to get over the idea that they are here to do something or acheive something for God's benefit. God doesn't need you. The bottom line of church, the sine qua non of Christianity, is not to do something but to be what Christ has made us; is not to acheive something but to receive what Christ has given us. Our focus on technique and "leadership" takes us away from the source, for "neither he who plants nor he who waters is anything, but only God, who makes things grow." Churches that are faithful to being and receiving will likely see growth, but when it happens they will know it is God's work and not their own and they will know that what is being built is a living temple and not a tower of babel that God will have to knock down at some point. Even if they don't see growth they have still fulfilled their purpose, "to declare the praises of him who has called us out of darkness into his wonderful light."