Saying “I will” do something is a lot different from saying “I could,” “I might,” “I can” or “I should.” It requires commitment. It’s transformative. That’s the premise behind Thom Rainer’s latest handbook for church members that describes nine traits of an outwardly focused Christian.

“I will” is a follow-up to his best-seller, “I am a Church Member.” In this excellent resource for both new and long-time members, the president of LifeWay Christian Resources encourages would-be disciples to take the next crucial step: moving from a right attitude (“I am”) to a right action (“I will).

“It’s really basic,” Rainer acknowledges. “It’s a matter of learning what the Bible says about being a part of the body of Christ. It’s about hearing His voice through His word.”

But then comes the hard part for many disciples: “And when Christ asks you to serve Him and others in His church, you should have one joyous response. Of course, by now you know the response,” he adds. “I will.” Let’s admit it. It’s easier just to reply, “I’ll pray about it,” and then NOT.

It doesn’t take our children long to realize that when someone says, “We’ll see,” what he or she really means is “not likely.” They retreat disheartened, sulk or, worse, throw a tantrum. We often play a similar semantics game when it comes to church, but God knows our true heart—and it usually doesn’t take long for others to figure it out, either. That’s one reason many become disheartened and disillusioned with the church, Rainer suggests.

The transformative power, he says, begins when we choose, instead, to adopt the attitude of Christ, highlighting Philippians 2:4-5. Beyond leading church members to declare, “I will have the attitude of Christ and put other church members before my wants and desires,” Rainer calls them to make some essential commitments: to worship with others, to grow together in a small group, to serve, to go share the gospel, to give abundantly and joyfully, to focus on positive ways God is using the church, to become an instrument of revival, to make a difference for Christ.

Imagine what could happen in our churches if we all became instruments of revival. It would be … transformative.

“It is time for church members to become a part of a movement where self is sacrificed and the body of Christ is strengthened. It is time to seek to bring glory to God through His church. It is time for a real revival of the hearts of church members,” he urges. “So beginning this moment, become the type of church member who will be used by God to be an instrument of a movement of revival in our churches.”

“I do.” Say the simple phrase, and people immediately associate it with wedding vows. It connotes making a life-time commitment to someone. Saying “I will” should too. The two-word phrase should just as immediately be associated with our commitment to God. As disciples of Christ, “I will” should be our ready response to serving others.

In a moving commissioning service at Highview Baptist Church in Louisville, Kentucky Baptists witnessed 34 disciples, including three Kentucky couples, say “I will” go wherever He leads and tell others about Jesus. They join approximately 4,800 missionaries seeking to share the gospel in some of the darkest and most difficult places around the world.

In a rousing challenge, International Mission President Platt proclaimed, “God is worthy of more than “nominal, casual, comfortable Christianity.” More than mere casual acceptance, the gospel elicits “total abandonment,” he said. “This gospel beckons us to abandon plans and dreams and possessions and priorities and treasures and pleasures in this world.”

Jesus told a story about a man with two sons in Matthew 21:28-31. The father instructed his sons to go work in the vineyard. The first son refused, but later obeyed and worked in the vineyard. He ultimately did the will of his father. The second son quickly said, “I will,” but actually disobeyed and did not work in the vineyard. Jesus likened the first son to tax collectors, prostitutes and other outcasts of Jewish society because they accepted Him as the Messiah and turned from their former disobedient ways. Jesus pronounced judgment on the leaders of Israel, who were likened to the second son who, although he first stated he would obey, did not do the will of the father.

Which son are you most like? Does your “I will” mean something?