This is the one who came by water and blood, Jesus Christ, not with the water only but with the water and the blood. And the Spirit is the one that testifies, for the Spirit is the truth. There are three that testify: the Spirit and the water and the blood, and these three agree. If we receive human testimony, the testimony of God is greater; for this is the testimony of God that he has testified to his Son. Those who believe in the Son of God have the testimony in their hearts. Those who do not believe in God have made him a liar by not believing in the testimony that God has given concerning his Son. And this is the testimony: God gave us eternal life, and this life is in his Son. Whoever has the Son has life; whoever does not have the Son of God does not have life. I write these things to you who believe in the name of the Son of God, so that you may know that you have eternal life. (1 John 5:6-13, NRSV)
The water and the blood testify and so does the Spirit. All of these testify that Jesus is the only Son of God and because of Him we have eternal life.
Whoever has the Son has life, eternal life. Whoever believes in the name of the Son of God has eternal life. Not will get. Or may acquire. You have eternal life.
John wrote these things so that you may know that you have eternal life. You are living eternally now with Jesus!
So go and proclaim that all may have eternal life. If they but believe in the name of Jesus!