1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life— 2 the life was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us—
For John, it was simple. He wanted everyone to know the real Jesus, even those who got Jesus wrong. John knew about Jesus like no one else still alive in his time. He had been with Jesus when He wept in the Garden of Gethsemane, had watched Jesus raise Lazarus and others, and had stood at the foot of Jesus' cross with Mary. He had leaned on Jesus during the Last Supper, had run to Jesus' empty tomb with Peter, and had eaten with Jesus after his resurrection. John saw the real Jesus, wanted his followers to know Him, and wants you to know Him as well.
John says he had "seen" Jesus
More specifically, he said he saw Jesus with his eyes. He didn't want there to be any confusion. Jesus was not a dream or hallucination. Jesus was not a spiritual being. No, John had watched Jesus, not in the metaphorical or imaginative sense, but with his eyes. He had seen the way Jesus looked at the beleaguered masses who were weighed down by religiosity and legalism. He saw the way Jesus touched the lepers and healed the sick, a foreshadowing of His coming kingdom. He saw how Jesus overturned the tables of the moneychangers and spent time with sinners. And what a life he saw! In watching Jesus, John was watching the perfect revelation of man. In his humanity, Jesus was everything that Adam and we were intended to be. He was flawless. He was bold. He was love.
John says he "heard" Jesus
And indeed he had heard him. He had listened to Jesus pour out his teachings to the masses, noting when Jesus opened his Sermon on the Mount with, "Blessed are the poor in spirit, for theirs is the kingdom of heaven" (Matthew 5:3). He heard Jesus weep and mourn over people, but he'd also heard Jesus pray, saying things like "My Father, if it be possible, let this cup pass from me; nevertheless, not as I will, but as you will." (Matthew 26:39). And he'd heard Jesus cry out to God and others while upon the cross, praying for forgiveness for those who crucified Him, promising Paradise for a believing criminal next to Him, and, as He became sin for us, crying out, "My God, My God, why have you forsaken me?" (Matthew 27:46). He heard Jesus, after three hours of darkness on the cross, say he was thirsty, drink, and then cry, "It is finished!" (John 19:28-30). Finally, he heard Jesus say, "Father, into your hands I commit my spirit" (Luke 23:46). And, before that, while Jesus was on His cross, John had heard Jesus' directions to his mother and John: "Woman, behold your son." And then to John, "Behold your mother" (John 19:26-27). Yes, John had heard Jesus.
John calls Jesus "the word of life"
This title might sound familiar to you on two levels. First, it reminds us of John's gospel, where he referred to Jesus as the Word -- or logos of God. And Jesus is indeed the eternal Son of God who, through His incarnation and substitutionary death, shows us the invisible God. But Jesus is also the word of life in that he is the message about life, showing us the way to the Father. You see, Jesus came to show us the way to true life. You can say you have God all day long. You can say you are spiritual all day long. You can say you feel close to God when (fill in the blank). But if you have tried to find spirituality or holiness or deliverance or morality or joy without Jesus Christ and His message, you haven't gotten the real thing. During John's day, people walked around saying they had God, but since they had rejected the Son God had sent, they were walking around deceived. Conversely, if you have believed Jesus to be the Son of God who came in human flesh, substituted himself for the sin of the world, and rose from the dead, if you have trusted him alone for the cleansing of sin, and as your pathway to God, then you have received the word of life.
Conclusion
So, John, like a loving dad, sat the church down and told them of the real Jesus he knew. Don't allow yourself to be persuaded to abandon the real Jesus Christ, the Son of God. In our age, everything will come against such a confession. You will be told you are unscientific, but the Bible makes ample room for science if one is willing to think about it. You will be told miracles aren't possible, but this is merely a presupposition one makes when they do not believe in God. You will be told that to believe God's Son came to earth, let alone believe in God, is nothing but superstition. But it is obvious every single thing we observe in nature had a cause, so it makes abundant sense there is a "Causer" who was without cause, a perfect and powerful and good being, for he's always been. You will be told Jesus was merely a teacher or prophet or all-around good guy who was so awesome his followers made up a whole story so they could build a religion around him. But these "followers" suffered and died for their confession, hardly a desirable outcome, and not one you would hold onto a myth for. Proclaim the true Jesus. Those who do will be rewarded.