Ephesians 4:1-3 is critical. “I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called, with all humility and gentleness, with patience, bearing with one another in love, eager to maintain the unity of the Spirit in the bond of peace.” Whatever the person sees that may need to be changed, they should not forget their calling and the manner in which they should walk: humble, gentle, patient, forbearing, and eagerly maintaining unity.
If the church is preaching the gospel, then I think most other aspects of church growth and change should be viewed with both eyes toward grace and love--which means the speed of the change isn’t the main criteria for progress or joy in the church. There are no perfect churches, and becoming frustrated with the pace of change suggests at least one of three things: pride; ignorance about what it takes to change a church and Who actually changes it; and/or an approach to the church that views the church mechanically, almost like a model car project/hobby requiring a little glue and finesse to put all the pieces together.
The church is not a project to be “fixed,” but a people to be loved (Eph. 5:1-2). We need to keep that in view as we look out on our various imperfections. And we need to keep the evidence of God’s plentiful grace in view as well. The frustrated person might be helped to find a couple friends in the church who are doing well piritually, who seem to be pleased with the church, and sit with them listening to all the evidence of grace they see and are encouraged by. A little more perspective is
probably in order in most cases.
Over at the New Attitude blog, Thabiti gives a great answer to the question, "What would you say to someone who sees where their local church is weak and needs to change and is frustrated that it's not changing fast enough?"