‘And you (‘He has raised from the dead', or ‘He has made alive'), when you were dead through your trespasses and sins.'
The ‘and you' may refer back to ‘raised Him from the dead and made Him to sit at His right hand' in Ephesians 1:20, or refer forward to the ‘make alive' in Ephesians 2:5 (the words in brackets are not in the Greek text, but are assumed). In the light of verses Ephesians 2:5-6 the first seems preferable, for it then sees His people as united in Him in all that happened to Him from Ephesians 2:20 onwards, but the final idea is the same in both cases. The thought is that His people have been ‘made alive' through spiritual resurrection (John 5:24-25) by being born from above (John 3:3), and created in Christ Jesus to good works as a result of His workmanship (John 3:10), have been made one with Him. As a result in the spiritual realm they share His throne, something which is to be followed eventually by literal ‘physical' resurrection (John 5:28-29). In other words from the moment of believing they reign along with Him in life and in death. It is a parallel thought to that in Isaiah 57:15, where as the High and Lofty One Who inhabits eternity, He dwells with those who are of a humble and contrite spirit, but it is made more significant in the long run because it involves finally sharing Heaven with Him.
This unity with Christ ties in with the previous reference to His people as His body (Ephesians 1:23), as those who are united with Him in His body as One in His saving purpose. It expresses the closeness of Christ with His own. This conception of corporate personality, where the many are seen as one, occurs regularly in the Old Testament. The Servant of God in Isaiah is seen as the people of Israel (Isaiah 41:8 and often); as both them and the Great Prophet (in Isaiah 42, 49); and as uniquely the Great Prophet Himself (in Isaiah 50, 53), while in the New Testament the Servant is Jesus Himself (Mark 1:11; Luke 9:35; Luke 22:37) and also the witnessing church (Acts 13:47). The ‘son of man' in Daniel is both the saints of the Most High (Daniel 7:27) and their Messianic king (Daniel 7:13), in each case one and yet separate. So all that Jesus experiences He shares with His people.
‘And you He raised from the dead when you were dead through your trespasses and sins.' Their condition had been that they were spiritually dead, and doomed to final death, because of their trespasses and sins. But now He has made them alive, and they vibrate with His life. ‘Trespasses and sins' is intended to cover all aspects of moral failure, both positive and negative. They had done what they should not have done (Romans 3:23), and had failed to do what they should have done (James 4:17), and were spiritually dead. But He raised them from the dead through the power of His resurrection life, making them spiritually alive. He transferred them from being under the power of darkness to being under the Kingly Rule of His beloved Son (Colossians 1:13).