Editor's note: For research purposes, Dr. Thom Rainer classified unchurched people into five categories, U1 through U5. U1 is the most receptive group to the gospel and U5 is the least receptive.

More than 17 million people will accept Christ if presented with the gospel. Another 43 million are close. I realize that statistics cannot speak for the mind of God nor presume upon the sovereignty of God and I also realize that our research is fallible, so I am making these declarations very carefully.

Our research estimates that there are 160 million unchurched people in America. This assumption is based on our surveys of more than 2,000 people, asking them how often they attend church.

If they said five times or less in a year, we classified them as unchurched. Now, among the unchurched, 11 percent are U1s. Remember, a U1 on the Rainer scale is someone who is highly receptive to the gospel; many U1s are waiting on God's messenger in order to accept Christ.

If the 11 percent hold for all the unchurched in North America, that means that more than 17 million people are waiting to hear the gospel. Where are the Christians to share Christ?

Consider one more issue. Another 43 million Americans are U2s. On the Rainer scale, that means that they are open and receptive to the gospel. Again, the vast majority of the receptive unchurched people in America told us that no one had ever invited them to church or shared the gospel with them.

Do you see what a difference you could make? You may think that you could never tell someone about Christ. While I would probably disagree with your self-assessment, I know you could invite someone to church. That simple act could make an eternal difference. How will you respond?

— Dr. Thom Rainer, "The Unchurched Next Door," Zondervan, 2003