11And the testimony is this, that God has given us eternal life, and this life is in His Son. 12He who has the Son has the life; he who does not have the Son of God does not have the life. 13These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life.
It is one thing to be secured in our salvation; it is another thing to be assured of our security. The doctrine of eternal security separates conservative Christians, due in part to differing interpretations of what we might call warning passages (for example, Hebrews 6:3–9 and its relationship to other passages like Romans 8:28–39). But the divide is also due to different understandings of assurance. Those who believe a genuine Christian can fall away from faith would tie assurance of salvation to ongoing faithfulness. Assurance, in that case, comes from seeing the character and trajectory of one’s life. On the other hand, those who believe that a genuine believer can never lose his or her eternal life would tie assurance to the knowledge of the truth and not to behavior.
John has been making the case that we should be able to see the genuineness of faith in our actions and attitude of love. Lacking love, a person’s confession of faith is questionable in the first place. John nowhere suggests that a Christian who has genuine faith, as verified in his outward behavior of love toward others, can lose his standing of salvation and eternal life. John writes of the genuineness of faith, not of losing the faith.
From the way John is writing this letter, we sense that Christians in his day were questioning whether they or others had genuine faith. Where there is carnal, selfish living, the question arises whether there is true faith or just a lookalike.
John brings this to a point: what does an individual think about his own faith? Does he or doesn’t he have eternal life? Paul issued this challenge:
Test yourselves to see if you are in the faith; examine yourselves! Or do you not recognize this about yourselves, that Jesus Christ is in you—unless indeed you fail the test? (2 Cor. 13:5)
The struggle was not in apostolic days only; even now, Christians sometimes struggle with whether or not their conversion was real—did they “do it right”? Was it merely an emotional experience or a real spiritual transformation? Sometimes we hear someone say, “But I don’t feel like I am saved” or, “How do you know I believed enough or with the right kind of faith to be saved?” John answers these questions in this passage, and it is vital that we understand this teaching of assurance and its relevance for our lives today.
Lord, I look to Your Word to settle the issue of whether I am saved or not!

God has promised Eternal life as said in John 3:16 For God so love the world….so we just believe it we Will have eternal life. I