New Living Translation
But those who obey God’s word truly show how completely they love him. That is how we know we are living in him.

American Standard Version
but whoso keepeth his word, in him verily hath the love of God been perfected. Hereby we know that we are in him:

Berean Study Bible
But if anyone keeps His word, the love of God has been truly perfected in him. By this we know that we are in Him:

Douay-Rheims Bible
But he that keepeth his word, in him in very deed the charity of God is perfected; and by this we know that we are in him.

English Revised Version
but whoso keepeth his word, in him verily hath the love of God been perfected. Hereby know we that we are in him:

King James Bible
But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.

World English Bible
But whoever keeps his word, God's love has most certainly been perfected in him. This is how we know that we are in him:

Young's Literal Translation
and whoever may keep his word, truly in him the love of God hath been perfected; in this we know that in him we are.

1 John 2:5 Additional Translations ...