You silly little man! The 12 were activly engaged in taking the gospel into all the world until God started a new thing with Paul. This was not a failure on the part of the 12. It was a falure on the part of Israel, who rejected the Father.
God never sent the unbelievers of Israel to do anything.
Paul did not start a new thing.
Paul began doing what all of the church was doing in preaching the gospel to the nations.--
Act 11:1 And the apostles and brethren that were in Judaea heard that the Gentiles had also received the word of God.
Act 11:2 And when Peter was come up to Jerusalem, they that were of the circumcision contended with him,
Act 11:3 Saying, Thou wentest in to men uncircumcised, and didst eat with them.
Act 11:15 And as I began to speak, the Holy Ghost fell on them, as on us at the beginning.
Act 11:16 Then remembered I the word of the Lord, how that he said, John indeed baptized with water; but ye shall be baptized with the Holy Ghost.
Act 11:17 Forasmuch then as God gave them the like gift as he did unto us, who believed on the Lord Jesus Christ; what was I, that I could withstand God?
Act 11:18 When they heard these things, they held their peace, and glorified God, saying, Then hath God also to the Gentiles granted repentance unto life.
LA