The roles and interactions between Peter, James, and Paul.
The Lord God Almighty utilizes imperfect and broken vessels to bring about his divine and perfect purposes. MacArthur expands, “God uses various means to bring blessing, strengthen faith, and cultivate spiritual growth in the lives of his people.”  The Sovereign Lord of the universe has created good works for his people (Ephesians 2:8-10; Titus 2:11-15). Peter’s citation of Joel 2:28-32 in his sermon at Pentecost and the fulfillment of this prophecy expresses a revolutionary change in the dynamic of redemptive history. No longer would the Holy Spirit temporarily empower and depart, but he would abide in believers permanently with no regard for status, gender, or age. All believers would possess this indwelling of the Holy Spirit, and his empowering prepares and enables Christians for service and worship. D.A. Carson adds,
“Because they have received the Spirit of God, they are also capable of saying something wise and true about the way the world appears to God. They can talk about the beauty of holiness, about God’s plan of redemption and reconciliation, about the judgment to come and the nature of our desperate plight. In sum, they can talk about Christ crucified.” 
Christians are empowered for the divine purposes of God. Therefore it is profitable to examine, consider, and learn from those of significant influence in Church history. Three of the most influential men to consider are Peter, James, the Lord’s brother, and Paul. Scripture leaves no room for doubting the contributions towards Christianity from each of these men and their role in developing the universal Church.
There are multiple men named James in Scripture, so a distinction must be made between them. James, the apostle, was the first apostle to be martyred in Acts 12:2. James, the brother of Jesus, would not become a believer until he witnessed Jesus resurrected. From there, he would become a leader in the Jerusalem church (Galatians 1:19). He would later preside over the Jerusalem council concerning the inclusion of the Gentiles into the kingdom of God (Acts 15). James’ martyrdom would occur in A.D. 62 at the hands of the Sanhedrin and was recorded by Josephus in Antiquities.
James played an instrumental role in the Early Church. He was not the apostle to the Jews or Gentiles like Peter and Paul, respectively. However, he became known as one of the pillars of the church (Galatians 2:9), and his conversion took place upon witnessing the resurrection of Jesus (1 Corinthians 15:7). Early church tradition and sources, like Hegesippus, identify him as “James the Just.” The Reformation Study Bible adds, “testifying to his extraordinary godliness, his zeal for obedience to the law of God, and his singular devotion to prayer. It was said that James’ knees became so calloused from prayer that they resembled the knees of camels. The epistle written by James is believed to have been written between A.D. 44 and A.D 62. James would have likely interacted with Peter much more due to his presence and role in the Jerusalem church where Peter was an elder (Galatians 2:7-10; 1 Peter 5:1) and apostle to the Jews. Church tradition places James as the first bishop of Jerusalem. James’ contributions to the Early Church are explicit, and he showed himself to be faithful. Within that context, he undoubtedly served side by side with Peter in the Jerusalem church until his martyrdom in A.D. 62.
The maturation and development of Peter are seen through the Gospels, the Acts, and the epistle that he penned. Peter would develop from a rash, impertinent young man into a wise, patient, and mature elder (1 and 2 Peter). Unger expounds on this development,
“The contrast between Peter of the gospels—impulsive, unsteadfast, slow of heart to understand the mysteries of the kingdom—and the same apostle as he meets us in the Acts, firm and courageous, ready to go to prison and to death, the preacher of the faith, the interpreter of Scripture, is one of the most convincing proofs of the power of Christ’s resurrection and the mighty working of the Pentecostal gift.”
Peter would often be viewed as the mouthpiece or representative of the disciples (Matthew 16:16; 19:27; Mark 8:29; Luke 24:41). Despite his eminence, he never gathered power beyond his apostolic position, calling himself a brother and an elder rather than an apostle in 1 and 2 Peter. Peter’s first interaction with Paul takes place in Acts 9:26 and Galatians 1:17-18. Despite facing a rebuke from Paul, Peter responded adequately to the rebuke and not only considered Paul an apostle but that his writings were inspired Scripture (2 Peter 3:15-18). Peter would ultimately be martyred in Rome by A.D. 68 through an upside-down crucifixion.
Although Paul, by his own words, was a latecomer of an Apostle (1 Corinthians 15:8-9), his role as the apostle to the Gentiles would influence redemptive and human history forever. Paul would go from vehement and zealous destroyer of Christians to the apostle for the Gentiles and would face his end as a martyr for Christ, as MacArthur excellently states,
“No one intimidated him. On the contrary, his driving ambition was to stand in the throne room of the Roman capital, give his testimony in Caesar’s presence, and thereby preach the gospel to the world’s most powerful ruler in the hub of the largest, most far-reaching empire the world has ever seen.”
Paul’s missionary journeys would minimize his interactions with Peter and James since they were ministering in Jerusalem, but his early development as an apostle saw progress in their affirmation of Paul’s genuine conversion in Galatians 2:7-9, which reads,
“On the contrary, when they saw that I had been entrusted with the gospel to the uncircumcised, just as Peter had been entrusted with the gospel to the circumcised (for he who worked through Peter for his apostolic ministry to the circumcised worked also through me for mine to the Gentiles), and when James and Cephas and John, who seemed to be pillars, perceived the grace that was given to me, they gave the right hand of fellowship to Barnabas and me, that we should go to the Gentiles and they to the circumcised.”
The next significant interaction between these three would take place at the Jerusalem Council in Acts 15. The remainder of Acts would focus on the journeys and travels of Paul, culminating in his arrest in Acts 28. Paul would eventually be martyred by decapitation in A.D. 67.
The roles and interactions between Peter, James, and Paul were instrumental in the birth, growth, development, and maturation of the Church of Jesus Christ. God The roles and interactions between Peter, James, and Paul were instrumental in the birth, growth, development, and maturation of the Church of Jesus Christ. God utilized these faithful men to bring about his divine purposes, reveal mysteries long wondered, and fulfill prophecies concerning the salvation that God would bring. The study of Peter, James, and Paul shows that God uses weak vessels for His glorious purposes. Christians need to understand that the same Spirit empowers them.
 John MacArthur and Richard Mayhue, Biblical Doctrine (Wheaton: Crossway, 2017), 780
 D.A. Carson, The Cross and Christian Ministry (Grand Rapids: Baker, 1993), 66
R.C. Sproul, Acts: An Expositional Commentary (Sanford: Reformation Trust, 2019), 176-177
 Flavius Josephus, Josephus: The Complete Works (Nashville: Thomas Nelson, 1998), 20.9.1
 R.C. Sproul, The Reformation Study Bible (Sanford: Reformation Trust, 2015), 2223
 D.A. Carson and Douglas J. Moo, An Introduction to the New Testament, (Grand Rapids: Zondervan, 2005), 627
 Examples of his “youth” are evident through many of his interactions within the Gospels including his rebuke and rebuking (Matthew 16:16-23), misguided magnanimous behavior (Matthew 18:21), sword play (John 18:10), denials (Mark 14), and his fear of the circumcision party (Galatians 2:12)
 Merrill F. Unger, The New Unger’s Bible Dictionary (Chicago: Moody, 1988), 993
 Sproul, Reformation Study Bible, 2237
 John MacArthur, The Gospel according to Paul (Nashville: Harper Collins, 2017), xv-xvi
 Unger, The New Unger’s Bible Dictionary, 977