Certainly if fear is at least viewed as a reverent respect for someone then obedience is the fruit or outward sign of that inward attitude. This is generally true in all "vertical relationships" - those relationships involving authority and subordination - such as parent/child, government/citizen, husband/wife and so forth. The manner in which the one under authority shows love towards the one in authority is through submission - which in practice means through obedience. For where there is no obedience neither is there submission.
But what is this "walking in darkness" part? Doesn't Jesus say, "Whoever follows me will never walk in darkness, but will have the light of life."John 8:12 But realize that the Messiah had not come at this point. In fact even during his ministry Jesus warned them of having limited opportunity to walk in the light, "You are going to have the light just a little while longer. Walk while you have the light, before darkness overtakes you. The man who walks in the dark does not know where he is going. Put your trust in the light while you have it, so that you may become sons of light." John 12:35,36 Here he was speaking to seekers, no doubt many of whom did not continue to follow him.
Up to the coming of the Messiah even the godly were darkened in their understanding of what we know now as the gospel of grace. They had to just trust God to reveal the path at the proper time as Paul writes, "I have become its servant by the commission God gave me to present to you the word of God in its fullness— the mystery that has been kept hidden for ages and generations, but is now disclosed to the saints." Col 1:25,26