While he may have warned about false prophets to come, did Jesus (pbuh) ever say that there definitely will NOT come a true prophet after him?
There is no need for anymore prophets, Jesus has revealed the Father of all creation to us. Any one else is a false prophet. The only prophets are those who confirm the Word of God, not change it, or add to it, or invent another. Jesus proved he has the keys to death and life, because he took on flesh, buried it, and raised from the dead, and ascended into heaven. Who ever has claimed to take life and give it again, only God can do this, anyone else is a false prophet
I do not believe that he ever said that he would be the last prophet to be sent by God.
Jesus did not have to say it, he did it. Besides Jesus did not have to write his message from God, he performed it, and finished it his gospel message. The written part are letters to inform the world by the eyewitness accounts.
In any case, let us analyse the Biblical passage that you quoted.
What is the name of this “other gospel” that Paul was very likely referring to in these verses from the Bible?
I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel:
Which is not another; but there be some that trouble you, and would pervert the gospel of Christ.
But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
As we said before, so say I now again, If any [man] preach any other gospel unto you than that ye have received, let him be accursed. (Galatians 1:6-9)
In order to determine the answer to this question, we need to examine historical evidence.
The apostle Barnabas died in 61 CE and the gospel that he was widely believed to have wrote was compiled in 51 CE.
The Epistle to the Galatians was not written before 54 to 58 CE and considering that no other gospel was in existence at this time and since it is also known that Barnabas was indeed preaching some “gospel” contrary to that of Paul’s during this period, it is therefore logical to believe that the gospel that Barnabas wrote is very likely indeed to be the “other gospel” that Paul was referring to in Galatians
Most Christians would contend that the Gospel of Barnabas is a fraud but I would submit that given the differences and subsequent parting of ways between Paul and Barnabas, the gospel that Barnabas preached was indeed the gospel that Paul warned about when he wrote his Epistle to the Galatians.