God, in His goodness and love, has not called us to be Christians alone. Though we individually sin, and are called out of the world individually, we are also called to come together in a local assembly. This assembly is called, in the New Testament, a church. Today many books on the market and speakers on the circuit are asserting that almost every conceivable attribute, worship style, computer program, book, sound system, seminar, ministry, education, program, group, philosophy, methodology, doctrine, virtue, spiritual encounter, parking lot design or management structure is the key to a successful church. Who is right? How can you tell if a church is healthy? How can you tell if your church is healthy? What can you do to encourage biblical, sustainable, God-glorifying growth? This little book is a tool to change churches. In it I suggest nine distinguishing marks of a healthy church. These are not the only attributes of a healthy church. They are not everything one would want to say about a church. They are not even necessarily the most important things about a church. For example, baptism and communion are essential aspects of a biblical church, yet they are not directly discussed here. That is because virtually every church at least intends to practice them. The nine attributes discussed here are marks that may set a church apart, that may distinguish a sound, healthy, biblical church from many of its more sickly sisters. The nine marks discussed here are found too rarely today, and are therefore in special need of being brought to our attention and cultivated in our churches.