Peter grew up a good Jewish boy who never made himself unclean by breaking any of the laws. But God, in one sense, forces him to do an unclean thing by commanding him to enter into a Gentile’s home. Peter’s obedience teaches us what Christian obedience looks like.
Firstly, to the Christian, there is no absolute law. God does not follow universal laws, which would make him secondary. God defines what is good and what is evil. This goes back to the sin of the first human couple. They wanted to define what is good and evil. Good and evil is only derivative of God. So God says to Peter to no call unclean what God has declared clean.
Secondly, the Christian does not obey to make ourselves right. Our justification does not come from our obedience but only the grace of Christ. Peter does not go to the Jewish Christians with moral superiority. He simply shares with them his story and his obedience.
Thirdly, for the Christian, understanding comes from the risk of obedience. The vision only made sense to Peter when he saw the Gentiles receiving the Holy Spirit.
Fourthly, both the call and courage to obedience only comes in prayer. The Christian can be confident about the “voices” only when the Christian is already familiar with the voice of God through prayer.