Jesus has given the church a job to do. We will either succeed or fail at it. I define our success as fulfilling the Great Commission. Using this definition, every church should want to be successful!
What is the alternative? The opposite of success is not faithfulness, but failure! Any church that is not obeying the Great Commission is failing its purpose for existing, no matter what else it does.
Jesus defined faithfulness in terms of behavior - it is a willingness to take risks that require faith in order to be fruitful.
The clearest example of this is the Parable of the Talents in Matthew 25:14-30. The two men who doubled the talents the master gave them were called "good and faithfulservants." In other words, they proved their faithfulness by taking risks that produced fruit. They were successful at the task that they had been assigned, and they were rewarded for it by the master
The passive, fearful servant who did nothing with the talent he was given produced no results to show the master when he returned. He was called "wicked and lazy" in contrast to the two servants called "faithful" who produced results.
The point of the story is clear: God expects to see results (fruit) that demonstrate our faithfulness. While others defined faithfulness as orthodoxy, Jesus defined faithfulness as productivity!
Faithfulness is accomplishing as much as possible with the resources and talents God has given you. That's why comparing churches is an illegitimate way to measure success. Success is not being larger than some other church; it is bearing as much fruit as possible given your gifts, opportunities, and potential.
Christ doesn't expect us to produce more than we can but he does expect us to produce all that we can by his power within us. That is a lot more than most of us think is possible. We expect too little from God and we attempt too little for him. If you're not taking any risks in your ministry, then no faith is required to do it. And if your ministry doesn't require any faith, then you are being unfaithful.
How do you define faithfulness? –
Are you being faithful if you refuse to learn new methods that work?
Are you being faithful to the message if you insist on communicating it in an outdated style?
Are you being faithful if you insist on doing ministry in a way that is comfortable for you even though it doesn't produce any fruit?
Are you being faithful to Christ if you value man-made traditions more than reaching people for him?
I contend that when a church continues to use a method that obviously isn't working- that is unfaithfulness!