Summary: Confidence in our salvation is essential to vibrant life as a Christian. John writes to encourage believers to focus on what is essential for vigorous faith.
“I write these things to you who believe in the name of the Son of God, that you may know that you have eternal life.” 
The couple, a man and a woman, had come to the door professing concern for my welfare. Their concern was driven by certainty that a great, world-wide conflagration known as Armageddon would soon be unleashed on the earth. They didn’t want to be caught up in that great battle, so they were working hard to secure their place in the safe zone God would provide. Their question feigned innocence—had I given thought to what was soon coming on the earth. Well, in fact, I had thought about what was coming. In fact, I had studied the issue at some length for a number of years. However, I informed them that I was much more concerned about living in the nasty now-and-now then I was concerned about the sweet by-and-by.
My response to their initial inquiries elicited another question from the woman: wasn’t I concerned that I might not be delivered when Jehovah at last unleashed Armageddon on the earth. At that, I reached for my Greek New Testament which was near the door, and asked, “Why would you want me to give up my certainty for your uncertainty? Why would you ask me to surrender to the dark unknown when I live in the bright presence of the Living Saviour?”
The question I posed led the woman to smugly comment that I didn’t know what I was talking about. They had studied the Bible and knew what it said; I couldn’t know what they knew. I opened the Testament that I was holding, pushing it toward her and saying, “Of course, you who trudge door-to-door peddling your error are all scholars and understand what the Bible says; what do you say about this verse?” I pointed to the verse that serves as our text and read, “Tauta egrapsa hymin hina eidete hoti zoen echete aionion tois pisteuousin eis to onoma tou huiou tou theou.” I explained, “You do see that John used the verb oida rather than ginosko to indicate that those who believe in the Name of the Son of God have an intuitive knowledge that they possess eternal life.” The couple had a rather startled look on their faces as they nodded blankly. I asked, “Do you have certainty that you possess eternal life?”
The woman was clearly startled by what I had said and the question I had posed to them. Suddenly, she exclaimed in a rather excited voice, “You must be one of the 144,000!”
“That’s not possible,” I explained patiently. “I’m not Jewish and I’m not a virgin.” Had these two individuals actually read the Word rather than reading about the Word in literature produced by a self-promoting cult which was ignorant of the Word, they would have known what God has done and the impact of His provision.
The purpose of the message today is to encourage believers, pointing to the certainty with which we are to live. May the Spirit of God direct our attention to the Word that He has given.
GOD HAS COMMUNICATED FOR OUR BENEFIT — Why should it be important for us to know that we possess salvation? Why does it matter whether we are confident in Christ or resigned to living life as a question mark? The answer lies in the purpose of salvation. Most of us will say that God loves us, and that is true. We have no doubt read JOHN 3:16: “God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life.”
Not long ago, an American actress married a British prince. The Episcopalian bishop that delivered the wedding sermon spoke on the theme of love, emphasising that God’s love was the foundation for the Gospel. Many Christians were thrilled that the wedding sermon was so lively at the otherwise staid wedding. I listened to the sermon; and it was a good sermon as far as it went, but it was incomplete. The reason Christians were pleased was that they believed that the message was biblical. Nevertheless, I harboured reservations about the bishop’s sermon.
I daresay that the average Evangelical Christian would likely argue that the message of Christianity is that “God loves me.” In fact, the average professing Christian would say that “God loves me enough to send His Son to die for me.” However, is this a biblical statement? “God loves me” is not the essence of biblical Christianity, because if “God love me” is the message we are to deliver, then who is the object of the Faith? “God loves me.” Me! Christianity’s object is me. Is this accurate? Is this what Christianity is all about?