The Apostle John of the Bible is one of the most blessed men to ever walk the face of the earth. Jesus met him when he was a young man, and immediately took him as an object of love. He walks besides Jesus and grows in knowledge and character. He builds experience to the point that he becomes a veteran of the Gospel. In his ministry, he becomes a pastor of the Church of Ephesus, which was founded by the Apostle Paul. He also becomes a prisoner of Christ when he gets banished to the terrible and isolated isle of Patmos, which was reserved for dangerous and desperate rejects of the Roman society. John sees it all.
In the end, he gets to write one of the four cornerstones of the Gospel. Then while at the Isle of Patmos, he receives a series of the most spiritual visions ever recorded by man, and he as a faithful scribe writes the Book of Revelation, the last of the New Testament. And when John gets old, he writes the three beautiful books, I John, II John and III John. He gets to experience every facet of a Christian life first as a young disciple, then as a young Apostle, then as a pastor and as a prisoner of Christ.
So when he says that which he has seen, he’s reflecting across the entire spectrum of his Christian life. He identifies Eternal Life from the beginning and mentions it in all the three groups of his books. But he doesn’t stop there. He emphasizes that he has seen Eternal Life with his eyes, he has looked upon it, he has handled it with his hands. He calls it the Word of Life.
Read 1 John again. When he says he is a witness and that he shows us the Eternal Life, which is the Father, we better listen. Of all the people that ever walked on earth, he is the definitely the right candidate to make such a statement.
Read it again.