That you may know - assurance desired

John writes so that believers might know that they have eternal life. If that is John's desire, then it should be our desire too, in accordance with God's revelation. This is a proper and legitimate desire for every believer. The New Testament assumes that true believers can and should know that they have eternal life, and that asking the right questions will help to obtain the right answers.

This is important because the assured believer is typically a comforted, confident, courageous, active and advancing Christian.