Being converted and becoming a member of the Lord’s church is one of the greatest experiences a person could have. However, there are people who have been baptized into the body of Christ, but they were not converted. The act of conversion is "a turning from and a turning to." In other words, the converted person has turned from walking in darkness to walking in the light (Luke 22:32). The primary purpose of this sermon is to remind believers of the need to continue walking in the light of Jesus Christ. It is also to remind believers that they can slip back into darkness regardless of how long they have been in the Lord’s church. Peter, one of Jesus' apostles, the one who preached the first gospel sermon on the Day of Pentecost, once failed from grace when he denied Jesus, not just one time, but three times. And we remember Judah Iscariot, one of the twelve apostles, who betrayed Jesus for thirty pieces of silver. Therefore, as believers, we need to watch as well as pray so that we will not fall into temptation (Matthew 26:41).