In contrasting the ministry of the twelve apostles with that of the Apostle Paul, we must observe carefully:
1⃣ The twelve were chosen by Christ ON EARTH (Luke 6:13) while Paul was later chosen by Christ IN HEAVEN (Acts 9:3-5; Acts 26:16).
2⃣ Prior to Paul’s conversion the twelve had known Christ only ON EARTH (I John 1:1). Even at His ascension to heaven “a cloud received Him OUT OF THEIR SIGHT” (Acts 1:9). But Paul knew Christ only IN HEAVEN, having never seen Him on earth (Acts 26:16; I Cor. 15:8).
3⃣ The twelve represented their own nation. The number twelve has no connection with the “one Body” of Christ. As we know, Jacob of old “begat the twelve patriarchs” (Acts 7:8). From these sprang the twelve tribes of Israel. These tribes had twelve princes over them (Numbers 1:16). Even when Israel was ruled by kings there were still to be twelve princes — one over each tribe (I Chronicles 27:22). Thus, as He went forth proclaiming “the gospel of the kingdom” our Lord chose twelve princes for the twelve thrones in the kingdom to come (Matt. 19:28).
On the other hand, Paul, as one apostle, represents the “one Body,” the Church of today (Rom. 12:5; I Cor. 12:13; Eph. 4:4). However, he was both a born Hebrew and a born Roman, so represented believing Jews and Gentiles “reconciled…unto God in one body by the cross…” (Eph. 2:16).
4⃣ The twelve were sent to proclaim Christ’s kingdom “at hand” (Matt. 10:7), and later to offer its establishment on earth (Acts 3:19-26). But Paul was sent to proclaim “the gospel of the grace of God” (Acts 20:24), while the kingdom is held in abeyance.
5⃣ The ministry of the twelve was based on covenant promises (Isaiah 60:1-3; Luke 1:70-79; Acts 3:22-26). Paul’s ministry was not based on covenant promises, but wholly on the grace of God through Christ (Rom. 3:21-28; 5: 20,21; Eph. 1:6,7; 2:7; etc.). source