“Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived; neither the immoral, nor idolaters, nor adulterers, nor sexual perverts, nor thieves, nor the greedy, nor drunkards, nor revilers, nor robbers will inherit the kingdom of God.” (1 Corinthians 6:9-10)
1 Corinthians 6:9-10 is interpreted in different ways by Bible students, but in my understanding of this passage, according to the context of the whole book of 1 Corinthians, Paul is warning the Corinthians that such behavior has serious consequences and that it is contrary to that which should characterize their lives as believers. Such behavior, of course, could be an indication that one was not a Christian since this so often characterizes the unbelieving world and in particular, the people at Corinth. But over and over again in this book, Paul shows that he is confident they were true believers in Christ. They were saved (cf. 1:2; 6:19-20).
The other possibility, and the one that fits the context of this book is that such behavior is the product of carnality—living out of fellowship with the Lord. Earlier Paul clearly states the Corinthian believers were carnal and were walking as though they were mere men, i.e., as though they were not saved when in reality they were. (cf. 1 Cor. 3:1-6). In fact, as Paul shows in 6:18-20, many of these believers were participating in the prostitution portion of the heathen temples of Corinth and were committing acts of adultery.
Further, when Paul, in 1 Cor. 6:9-10, speaks of not inheriting the kingdom of God, there is good evidence from the use of “inheritance” in Scripture, that he is not talking about getting into heaven. The heirs of the kingdom are its owners and rulers who reign and rule with Christ (see Rev. 3:21; 5:10; 20:4) and not just its residents. In other words, salvation, which provides us access to heaven and the eternal state is unchangeable. It is by grace through faith alone in Christ alone, but our inheritances in the kingdom are not unchangeable. Receiving one’s inheritance in the kingdom involves receiving special rewards and special privileges that come to a believer for faithful service. The loss of one’s inheritance is not the same as the loss of salvation. Salvation cannot be lost since it is a gift, free through faith.
There is an excellent book that covers many of these issues by Joseph Dillow called, The Reign of the Servant Kings. I would highly recommend it to you. It has an entire chapter or two that deal with the issue of inheritance as seen in both the Old and New Testaments. As further support for this, note that at the end of 1 Corinthians 6, where Paul exhorts these Corinthian believers to “flee fornication,” he clearly sees them not only as genuine believers and saved, but as indwelt by the Spirit. In fact, he uses this truth to challenge them to stop such behavior.
6:18 Flee sexual immorality! Every sin a person commits is outside of the body, but the immoral person sins against his own body. 6:19 Or do you not know that your body is the temple of the Holy Spirit in you, whom you have from God, and you are not your own?6:20 For you were bought with a price. Therefore glorify God with your body.
Salvation is by faith alone in the person of Christ. It is a free gift of God’s grace and not by works of righteousness which we have done either in avoiding sins or in doing positive good deeds (Eph. 2:8-9; Tit. 3:5). No matter how hard we try or how much we grow spiritually, we all still have sin in our lives (see 1 John 1:8-2:1). Does this mean we can sin as we please because where sin abounds God’s grace abounds (see Rom. 5:18-6:1f)? No, not at all, but not because sin causes us to lose our salvation, but because of the temporal and eternal consequences of sin like loss of fellowship, divine discipline in this life (cf. 1 Cor. 11:28-32), and loss of eternal rewards (1 Cor. 3:12-15), though heaven is guaranteed.
May I suggest that you begin to study through the ABCs for Christian Growth on our web site. It will answer nearly all of these questions in time. This study will begin to lay the foundation needed for real growth. I’d suggest reading the ABCs first, then try to get a copy of Dillow’s book mentioned above.