“And hereby we know that we are of the truth, and shall assure our hearts before him.”
King James Version (KJV)
3:19 And hereby we know - We have a farther proof by this real, operative love. That we are of the truth - That we have true faith, that we are true children of God. And shall assure our hearts before him - Shall enjoy the assurance of his favour, and the testimony of a good conscience toward God. The heart, in St. John's language, is the conscience. The word conscience is not found in his writings.
1Jo 3:19 And hereby we know that we are of the truth. Because our love is active and practical. And shall assure our hearts before him. Have a good conscience.