Albert Barnes Commentary Colossians 1:17

"and he is before all things, and in him all things consist." — Colossians 1:17 (ASV)

And he is before all things. As he must be, if he created all things. Those who regard this as referring to a moral creation interpret it as meaning that he has the pre-eminence over all things, not as referring to his pre-existence. But the fair and proper meaning of the word before (the Greek pro) is that he was before all things in the order of existence (John 11:55; John 13:1; Acts 5:36; Acts 21:38; 2 Corinthians 12:2).

It is equivalent to saying that he was eternal—for he who had an existence before anything was created must be eternal. Thus it is equivalent to the phrase In the beginning (Genesis 1:1; compare the notes on John 1:1).

And by him all things consist. In other words, they are sustained (see the notes on Hebrews 1:3).

The meaning is that they are kept in the present state; their existence, order, and arrangement are continued by his power. If unsupported by him, they would fall into disorder or sink back to nothing.

If this is the proper interpretation, then it is the ascription to Christ of infinite power—for nothing less could be sufficient to uphold the universe; and of infinite wisdom—for this is needed to preserve the harmonious action of the suns and systems of which it is composed. None could do this but one who is divine; and hence we see the reason why he is represented as the image of the invisible God. He is the great and glorious and ever-active Agent by whom the perfections of God are made known.