Insecurity in a relationship can be devastating. It can introduce fear, anxiety, depression, and anger. It can lead us to withdraw from or distance ourselves from the other person and lead us to over analyze and/or sometimes mistake that person's words or actions. The same can happen to a child of God when he/she is unsure of his/her relationship to God. John's talk of the love believers are to show each other could lead some sensitive believers to conclude they must not be born-again Christians at all. To counter this, John lets his readers know that God wants them to have a secure relationship with him and he points to the right source of assurance of a genuine born-again experience in this passage.