John said that he was rejoicing to find some children walking in truth. Is walking in truth separate from walking in Jesus? Some may think so, but John does not separate these. "Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son" (2 John 9). To walk in truth is to walk in Jesus, and to avoid truth is to avoid Jesus. When we avoid any area of truth, we lower God's standard, and diminish the character of God. God does not accept our standards, and does not lower His standard so that we can be accepted or "feel good" where we are. He has given Jesus Christ to dwell in us by the Holy Spirit, and in doing so, He raises us up to His standard. If we want to dwell with God, then we must walk in who He is, not in who we are.
What does it mean to walk in truth? If Jesus is truth (which He is), and if Jesus is in us by the Holy Spirit (if He is not, we are not His), then He will write His word on our hearts and on our minds. This is the promise of the New Covenant. When His word comes to us in a living relationship, our place is to respond to that word and work it out in our lives. It is God at work within us, both to will and to do His good pleasure. But our place is to work out that salvation with fear and trembling. (Phil. 3:12) If the Lord brings an area of truth before us which we will not walk in, or if we explain it away somehow, then we have rejected Jesus. He does not bring truth before us that is unnecessary or irrelevant. He always comes to us at the right time and with the grace to obey. We can never blame Jesus. He is perfect in all His ways.
The truth that Jesus brings may seem beyond us, but it is never beyond Jesus in us. He does not consider what we can do separate from Him, but what His grace can do in us. Our place is to believe Him when He speaks, and then to act in faith, leaving the results in His hands. When we reason according to our understanding, we cease to walk in truthin Jesusand our love relationship with Him is greatly affected.