Read Revelation 3:14-22
In Revelation 3, John records this letter from Christ to the church in Laodicea. Though it was written to a specific church a couple thousand years ago, it is still startling applicable to many Christians today.
The Lord voices a strong rebuke to this church for being "lukewarm" (16). Jesus wishes that the church would make a decision--either be on fire for Him or leave Him completely. Passively lying in between these two actions is detestable to Christ, and He wants to spit those people out of His mouth. So what does it mean to be lukewarm? In verse 17, we see that the Christians in Laodicea were rich. Because they already had all that they needed materially, they stopped depending on God and didn't think they needed Him anymore. They turned to their riches to bring them satisfaction rather than looking to the Lord. Their wealth led them to believe that they already had everything that they needed. However, Christ reveals their true condition in that same verse, calling them, "wretched, pitiful, poor, blind and naked." They were doing great materially, but they were poverty-stricken in a spiritual sense. What's worse is that they didn't even know it!
As a result of their sinful and complacent spiritual state, they are called to repent earnestly (19). Christ urges them to work for treasures in heaven ("gold refined in the fire"), to become pure and righteous ("white clothes to wear"), and to open their eyes to their own wretchedness ("salve to put on your eyes, so you can see") (18). Thankfully, our God is a God of mercy and forgiveness. When we sin, we are able to repent and be cleansed of our sin. However, repentance is more than just passive confession. It requires actively turning away from that sin and pursuing obedience.
In verse 20, Christ proclaims that He is standing outside the door and knocking; when the door is opened, He promises to come in and dine with the believer. This is not a verse about salvation (as many mistake it to be), but a verse about fellowship with Christ. The church of Laodicea was not abiding with Christ. They were living in sinfulness and consequently were out of fellowship with the Lord. This verse is about restoring that fellowship with Christ after repentance.
What is your current spiritual state? Are you lukewarm, hot, or cold? Is Christ waiting outside your door for you to repent and restore your fellowship with Him? I am scared to death of receiving a rebuke from Christ like the church of Laodicea did. Nevertheless, many times I find myself drifting into complacency, going through the motions of Christianity on autopilot rather than actively pursuing Christ and abiding in Him. Cry out to the Lord right now, repent of lukewarmness or whatever sin you are remaining in, and ask Him to make you "hot" today!