Answer
It's true that the Bible teaches that everyone who trusts in Christ alone as his or her savior, not in personal works or merit, is saved. At the same time, the Bible tells us in many places that not everyone who goes to church is saved, and that not even everyone who belongs to a church and who professes to be a Christian is saved -- not even everyone who makes a credible profession of faith and seems for all intents and purposes to be a sincere believer is saved (1 Pet. 4:17).
This is not because salvation depends on personal works, but rather because these people do not really believe what they say the believe. For this reason, the Bible sometimes tells us to examine ourselves to see if our faith is true (2 Cor. 13:5; 2 Pet. 1:10).
The term "lukewarm" comes from Revelation 3:16, where it describes professing Christians who do live as if their salvation depended upon Christ. The letter to the church of Laodicea from which this term comes is not written from the perspective of the omniscient God who knows who is actually saved and who is not, but is presented from the perspective of the prophet who is rebuking a church for their visible failures. Those who repented of their sin at reading this letter and who persevered until the end were saved. Those who did not were never saved at all, despite the fact that they were in the church (1 John 2:19). The prophetic letter was meant to move the sinning members of the church to repentance so that they would be saved.
Because churches contain both believers and unbelievers, they should always be proclaiming the gospel. In fact, even believers need to hear the gospel regularly so that they remember to live in dependence upon it. This is one of the functions of the Lord's Supper -- it visibly represents the gospel for us. The preaching should do the same thing; it should point us to the gospel and apply it to our lives, whether we are believers or unbelievers. Some churches do not recognize the importance of teaching the gospel to their people, and thus they may neglect this part of their responsibility. Others may just wrongly assume that they have no unbelievers in their congregations. On the bright side, many churches do understand the importance of consistent gospel-centered teaching, and do practice it.
Answer by Ra McLaughlin
Ra McLaughlin is Vice President of Finance and Administration at Third Millennium Ministries.