How did the Son become visible in the Old Testament?
The Son, the image of the invisible God, stepped out of the invisible triune God and became visible in the Old Testament economy temporarily, then He would disappear. In the New Testament, He became visible, tangible, and touchable, living in the flesh by virtue of Bethlehem.
Les explains from Colossians 1:15 that the pronoun “who” refers back to the Son in verse 13. The invisible God is the triune God—God the Father, God the Son, and God the Spirit—who are Spirit and were invisible. Out of that invisible triune God stepped the Son, and He became visible in the Old Testament economy temporarily, and then He would disappear. In the New Testament account, He became visible, tangible, and touchable. He lived in the flesh by virtue of Bethlehem. It is the same God, now manifested in the flesh by the Son.
Who is the image of the invisible God, the firstborn of every creature:
Who is the invisible God that the Son is said to be the image of?
The invisible God is the triune God—God the Father, God the Son, and God the Spirit. They are Spirit and were invisible. Out of that invisible triune God stepped the Son, who became visible, tangible, and touchable, especially in the New Testament through Bethlehem's incarnation.
How did the Son of God become visible in Old Testament times?
The Son, who is the image of the invisible God, stepped out from the invisible triune God and became visible in the Old Testament economy temporarily. After that, He would disappear, unlike His New Testament manifestation in flesh at Bethlehem.