"Look to yourselves, that we do not lose those things we worked for, but that we may receive a full reward."
2 John 1:8
The apostle John wrote the epistle of 2 John to a Christian woman and her children. Some have suggested it was actually written to a particular church because a specific name was not recorded. Regardless to whom exactly it was originally penned, as part of the divinely inspired Word of God it is profitable for all Christian believers who have ears to hear.
After exhorting the recipients of the letter to walk in Christ's love by keeping His commands, John issued a warning concerning many deceivers who had gone into the world. He did not warn them of shady people by name, but he explained in 2 John 1:7: "For many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist." Many deceivers were in the world when the church was still young, and I imagine the number of deceivers have multiplied exponentially. Instead of focusing on deceptions, John told them to look to themselves and ensure they were continuing in the love of Christ.
There is something in us which cares deeply about what other people believe and do. After Peter has been restored by Jesus and had been commissioned to feed Christ's sheep and follow Him, Peter immediately asked about what John was supposed to do. Jesus said, "What's that to you? You follow me." We naturally saddle ourselves with cares and worries about others. We may worry over the spiritual condition of an alcoholic and the potential destruction of relationships and family, but our anxiety can't fix the problem. Rather than obsess over the faults of others, wouldn't it be better for us to repent of our worrying which is a destructive sin as well? I can't make an alcoholic see his need to stop drinking, but I can choose to repent and obey God myself through the power of the indwelling Holy Spirit.
John's statement instructs us we need to examine ourselves, obey the commands of Christ, and refuse to give ground to deception in our lives. It is possible, based on this scripture, for people to not obtain a full eternal reward. Our salvation is secure based upon the atoning sacrifice of Christ on Calvary, but we can deny ourselves a full reward when we are not circumspect and cease examining our lives according to scripture. God provided a great inheritance of land in Canaan for the tribes of Israel, but not every tribe cared to drive out the enemies and secure their borders. They were cramped but comfortable enough, and their negligence allowed squatters to mar their inheritance.
God has an inheritance for every Christian in this life, and He has promised eternal rewards He delights to generously bestow upon all His faithful servants. Let us not lose the things we have worked for and lose ground because we have been deceived what we do or say doesn't really matter. Let us look to ourselves and live in the way which pleases God so we may receive a full reward. If God has a reward for me, by His grace I want to receive it in full. How about you?