And the Lord went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night: Exodus 13:21

The primary purpose of the pillar of cloud by day and the pillar of fire by night was to be a visible reminder to God’s people of His presence with them.
We must keep in mind that Jesus’ audience would have understood what He was saying in the context of which was a reminder of the pillar of fire that had guided them in the wilderness.
So, the first three aspects of who Jesus is are drawn directly from the nature and purpose of that pillar of fire.

In the opening words of John’s gospel, John describes Jesus as the true light who came to earth in order to be present among His people

Jesus, the true light, came into the world. He became flesh and dwelt among us.