Colossians 1:18

‘And he is the head of the body, the church: who is the beginning, the firstborn from the dead, that in all things he might have the pre-eminence.'

Not only does the old creation have its being from Him, but also the new creation. He is not only Lord and Head over all things (Ephesians 1:22) but also the Head, the Overlord, of the church, that gathering of people who have been united with Him in His body. Firstly because He is ‘the beginning', and secondly because He is ‘the firstborn from the dead'. Thus the aim is that as the Firstborn of all creation, the source and Lord of the old creation, and as the Firstborn from the dead, the source and Lord of the new creation, He should have total pre-eminence in and over all things.

‘He is the Head of the body.' This does not mean that we are to see Him as the head in heaven and we as, as it were, a body joined to that head, and representing Him on earth. It refers to His sovereignty over the body, a body which is made up of Himself and His people united with Him. As Ephesians 1:22 tells us, as Head He is not just the head of the church but the ‘Head over all things' to the church. His Headship stresses His supremacy, not a direct connection with the body. Consider how in 1 Corinthians 12 the body, which is Himself and His people, includes the head, all of whom are represented by it (1 Corinthians 12:16 where ear and eye are part of the body, and 1 Corinthians 12:21 where the head is contrasted with the feet, all within the body). So He Who is Head of creation (Ephesians 1:22 and implied here in Colossians) is also Head of the church (not as its head as opposed to its body but as its sovereign Lord).

‘Of the body.' The people of God are His body because they have been united with Him in His body. They have been crucified with Him (Galatians 2:20; Galatians 5:24; Galatians 6:14; Romans 6:5; Romans 7:4; Ephesians 2:16), they have risen with Him (Romans 6:4; Ephesians 2:1), they are one with Him (Ephesians 5:31; 1 Corinthians 12:12) and the bread at the Lord's Table represents both Him and them (1 Corinthians 10:16). To suggest that this speaks of the church as the ‘extension of His incarnation' is to miss the point completely. It does not mean that. It emphasises spiritual union within the body. The idea of the body is never as outward in relation to the world, but always as inward in relation to God and to each other. They are one  with  Him, and one with each other. They have been presented blameless ‘in the body of His flesh through death' (Colossians 1:22). For further treatment of this subject see the Appendix.

‘Who is the beginning.' He was its founder and commencer. It is ‘His church', which He would build on Peter's confession (Matthew 16:18). And He is its originator and the source of its life. He began it all.

‘The firstborn from the dead.' He is pre-eminent in resurrection and indeed the prime cause in the raising from the dead (John 5:26). He had the power to lay down His life and the power to take it again (John 10:18). It was only through His resurrection that the resurrection of others became possible (consider Matthew 27:52). We can live because He lived. And when He speaks all the dead will rise (John 5:28). Thus He is Lord of the resurrection.

‘That in all things He might have the pre-eminence.' Both old and new creation owe their being and continuing existence to Him. And the overall goal of the Godhead was His total pre-eminence.