Peter was a great apostle of Christ, a veritable pillar of the church (Galatians 2:9), but at times he could be weak.
Though he had been shown miraculously that the Gentiles were entitled to equal privileges in the kingdom of God (Acts 10), on one occasion, when in the presence of influential Jewish Christians who were close to James, Peter refused to socialize with Gentile brethren (and what might that suggest about James?). Paul addressed this matter in Galatians 2:11.
There are two points worthy of reflection.
First, Peter was acting like a hypocrite — and that is the precise meaning of the word “dissimulation” (2:13). As a consequence, the apostle stood “condemned.” This surely reveals that a child of God can so sin as to stand in a state of condemnation. This contradicts the philosophy of Calvinism.
Underline the word “condemned,” and record the implication of this term in your margin — Child of God can be condemned.
Second, observe that Paul did not hesitate to rebuke his fellow-apostle. Paul knew he was “not a whit behind” Peter (see 2 Corinthians 11:5), and he hesitated not to chastise him.
However, this action does not harmonize with the Roman Catholic notion that Peter was the head of the church on earth, the personal representative of Jesus Christ. This passage does not lend support to the concept of the primacy of Peter as advocated by Catholicism.
In your margin observe: No primacy of Peter here.