“If any man does God’s will,” Jesus told the crowd gathered around Him in the temple at the Festival, “He will know the doctrine, whether it comes from God, or whether I speak of Myself. Those who speak for themselves want glory only for themselves; but a person who seeks to honor the One Who sent him speaks the truth, not lies.”Jesus here makes a key point, as applicable to the Christian life as it is to ordinary everyday life; you must do something in order to actually know about it.
In my late teens, I studied welding. As I studied, I got the mental picture of how to do it; I could almost feel the motion in my hands, and see in my mind’s eye a straight, beautifully even, rippled finished weld. But when I actually did some welding, I discovered that it takes practice to acquire the skill. When I had completed a job that involved weeks of welding, I knew how to weld– but I also knew that my skill was limited to my experience.
Jesus said that, when we do God’s will, we will know that His doctrine comes from God. We can read the Bible and debate it all day long; in the end of the day, our knowledge of God’s doctrine will be measured by how much we step out in faith and obey His will.
The other key point Jesus made here is that a faithful messenger does not put himself forward, but conveys truthfully the message of the one who sent him. Jesus Himself had amazing credentials– Creator of all, Son of God, the Light of the World– yet He deliberately spoke as the Messenger of His Father. He spoke only His Father’s words, and did only His Father’s deeds. His hearers could either listen to the true words of God Himself, or reject them. They could debate endlessly about Who He was; but, in the end, it was what they did with what they had heard that mattered….eternally.