The Epistle of First John writes to those who believe, that they might know that they know they believe, and then really believe. In a word, we are looking for assurance, assurance of salvation. The two Gospel facts, remember, are these: the death and the resurrection of Jesus Christ. It was not just that God would forgive His people of their sins, but He would save His people from their sins. The evident assurance of your salvation is fruitfulness.
The Assurance Compass