Security and assurance

When thinking about the permanence of salvation, two words are commonly used: security and assurance. While they are related terms, they are not the same thing.

John MacArthur summarizes the difference well:

Many people lack assurance because they do not understand that salvation is an utterly divine, totally sovereign operation. Assurance is built on the historical reality of what Jesus Christ accomplished. It is not a feeling without reason, and you will never have the subjective feeling of assurance until you comprehend the objective truth of the gospel.

In other words, if you are a genuine believer, you are secure, whether you have the feeling of assurance or not. On the other hand, it is also possible for someone to mistakenly assume personal assurance, when he is not actually secured (saved). Genuine assurance is the result of confidence in the finished work of Christ on the cross.