Occasionally you will hear objection to the statement that Jesus acted as God while on earth. Some interpret the words, "God was in Christ" (2Corinthians 5:19) by inserting commas: “God was, in Christ, reconciling the world to himself ” which takes the punch out of the phrase "God was in Christ", suggesting that Jesus Christ was merely a tool of God, and not God himself.
People also try to water down the idea that God was in Christ by saying something like, "Well, when we say of a boy, “you can see his father in him”, we don't literally mean that his father is actually in him. We simply mean that he takes after his Father." The scriptures however do not permit of such an interpretation, and we are about to see why...
We will notice three actions of Jesus on earth that show that quite literally God was in Christ. He was God in the flesh and acting as God. There are certain things in which Jesus would have acted presumptuously if he were not God in this world.
We know that God was in Christ because people worshipped him and he did not object. By the way, the Greek word for worship is προσκυνεω (proskuneo Strong 4352) which means to do homage.
A leper “worshipped” Jesus (Matthew 8:2-3). After Christ rose from the dead, the eleven disciples “worshipped” him (Matthew 28:16-17). There are several other similar examples of people worshipping Jesus.
When Cornelius worshipped Peter, Peter protested (Acts 10:24-26). When John worshipped an angel, the angel protested (Revelation 22:6-9). But when people worshipped Jesus, he did not protest.
We know that God was in Christ because he forgave sins. Only God has the authority to forgive sins. If God was in Christ (in the sense that Christ was God in the flesh) then Christ could forgive sins. Jesus claimed this authority on earth showing himself to be God on earth (Luke 5:18-26).
We know that God was in Christ because he changed God’s Law. God alone has the authority to change his law. If God was in Christ (in the sense that Christ was God in the flesh) then Christ could change God’s Law. And he did.
In his sermon on the mount, Jesus replaced certain laws of Moses with new teaching. For instance, Jesus acknowledged that, in the Mosaic age, God permitted a man to divorce his wife and marry another. Jesus then gainsaid that law, and declared that divorce either causes adultery or is caused by it (Matthew 5:31-32). As another example, Jesus gainsaid the law of "Eye for eye, and tooth for tooth" (Matthew 5:38).
In the above three ways we see Jesus acting as God in this world. Who has the right to act as God unless they are God? Prophets and angels have represented God, but they never acted as though they were God. Jesus, by acting as God, showed himself to be God. God was in Christ in the fullest sense: "in him dwells all the fulness of the deity dwells in bodily form (Colossians 2:9).
If our conclusion needs added support, we can hear the testimony of John, both in his gospel and in his first letter.