KJV:
I have written unto you, fathers, because ye have known him that is from the beginning. I have written unto you, young men, because ye are strong, and the word of God abideth in you, and ye have overcome the wicked one.
NASB:
I have written to you, fathers, because you know Him who has been from the beginning. I have written to you, young men, because you are strong, and the word of God abides in you, and you have overcome the evil one.
KJV:
I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.
NASB:
I have not written to you because you do not know the truth, but because you do know it, and because no lie is of the truth.
KJV:
These things have I written unto you concerning them that seduce you.
NASB:
These things I have written to you concerning those who are trying to deceive you.
KJV:
These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
NASB:
These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life.
KJV:
And now I beseech thee, lady, not as though I wrote a new commandment unto thee, but that which we had from the beginning, that we love one another.
NASB:
Now I ask you, lady, not as though I were writing to you a new commandment, but the one which we have had from the beginning, that we love one another.
KJV:
Having many things to write unto you, I would not write with paper and ink: but I trust to come unto you, and speak face to face, that our joy may be full.
NASB:
Though I have many things to write to you, I do not want to do so with paper and ink; but I hope to come to you and speak face to face, so that your joy may be made full.