What does ‘walk in the light’ (1 John 1:7) refer to?

This text is from a transcript of a talk by David Gooding, entitled ‘Key New Testament Themes’ (1996).

That's a good question. Walk is a Hebrew metaphor for to live and behave. The men that came to our Lord in the Gospel of John, they physically came to him, because he was there present, so they came to him and they listened to what he said. Some of them, like Thomas and John and Peter, continued with him, stayed with him and, as he taught them, they abode in his word, continued in it. There were others that, when they heard what the Lord was exactly saying, turned back and they walked no more with him. And our Lord turned round to the twelve and he said, 'Will you also go away?' So here was 'walking' in the literal sense, when he was here on earth. They came to him and some of them continued with him. Others walked no more with him. They went back: in other words, they didn't follow him.

But then of course, the word takes on a deeper meaning. He's not here physically, but if I want to share the life of God, I must come and walk where God is, as God is in the light. I must come and walk in that light. I must come and walk daily with the Saviour.