“But these are written so that you may continue to believe that Jesus is the Messiah, the Son of God, and that by believing in him you will have life by the power of his name.”
The purpose of John in that verse is so that I may continue to believe that Jesus is my Savior, my Redeemer, my Lord, in every moment and season in my life, daily.
And by believing in Him continually I may experiencing His power in every moment and season in my life, daily, as well. Experiencing His power to forgive someone who did wrong and every time when the abusive words come to my mind and hurt my heart, I have His forgiveness power to forgive in His way.
That I may experiencing His power to love difficult people the Lord has put in my life, to love them the way He loves me. He gave His great love when I was a sinner, He doesn’t wait until I am good and upright first. I have His amazing grace power to love in His way.
That I may experiencing His power to accept others, to be kind, to pray, … anything… I really need His power to transform me continually and in continually believing in Him I would be well supplied.