New Revised Standard Version
because of the truth that abides in us and will be with us forever:

Contemporary English Version
We love you because the truth is now in our hearts, and it will be there forever.

New American Bible
because of the truth that dwells in us and will be with us forever.

Douay-Rheims Bible
For the sake of the truth which dwelleth in us and shall be with us for ever.

For the sake of the truth which dwelleth in us and shall be with us for ever.

the truth's.

1 Corinthians 9:23 And I do all things for the gospel's sake, that I may be made partaker thereof.

2 Corinthians 4:5 For we preach not ourselves, but Jesus Christ our Lord: and ourselves your servants through Jesus.

which.

John 15:7 If you abide in me and my words abide in you, you shall ask whatever you will: and it shall be done unto you.

Colossians 3:16 Let the word of Christ dwell in you abundantly: in all wisdom, teaching and admonishing one another in psalms, hymns and spiritual canticles, singing in grace in your hearts to God.

2 Timothy 1:5 Calling to mind that faith which is in thee unfeigned, which also dwelt first in thy grandmother Lois and in thy mother Eunice, and I am certain that in thee also.

1 Peter 1:23-25 Being born again, not of corruptible seed, but incorruptible, by the word of God who liveth and remaineth for ever. . . .

1 John 2:14,17 I write unto you, babes, because you have known the Father. I write unto you, young men, because you are strong, and the word of God abideth in you, and you have overcome the wicked one. . . .