A common misinterpretation of this passage is to read it as teaching that believers can lose their salvation by failing to 'keep in memory' the gospel, fostering unnecessary fear and insecurity; instead, it warns against an empty profession of faith that was never authentic, using 'believed in vain' to highlight self-deceived individuals whose belief lacks the power of genuine reliance on Christ's work, rather than implying that true salvation is fragile or revocable by forgetfulness.
I Corinthians 15:2
King James Version (1769)
2 By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain.
The core truth of 1 Corinthians 15:2 is that salvation is secured through the gospel of Christ's death and resurrection as preached by Paul, but only for those who hold it firmly in remembrance, distinguishing genuine saving faith from a superficial or 'vain' belief that produces no lasting fruit or transformation, emphasizing perseverance in the truth as evidence of true salvation within the context of affirming the resurrection's centrality.