As for the Jews, the Law covenant was abolished on the basis of Christ’s death on the torture stake (Col 2:14), and the new covenant became operative at Pentecost, 33 C.E. (Compare Ac 2:4; Heb 2:3, 4.) Nevertheless, God extended special favor to the Jews about three and a half years longer. During this time Jesus’ disciples confined their preaching to Jews, Jewish proselytes, and Samaritans. But about 36 C.E. God directed Peter to go to the home of the Gentile Cornelius, a Roman army officer, and by pouring out His holy spirit on Cornelius and his household, showed Peter that Gentiles could now be accepted for water baptism. (Ac 10:34, 35, 44-48) Since God no longer recognized the Law covenant with the circumcised Jews but now recognized only his new covenant mediated by Jesus Christ, natural Jews, whether circumcised or uncircumcised, were not considered by God as being in any special relationship with him. They could not attain to a status with God by observing the Law, which was no longer valid, nor by John’s baptism, which had to do with the Law, but were obliged to approach God through faith in his Son and be baptized in water in the name of Jesus Christ in order to have Jehovah’s recognition and favor.—See SEVENTY WEEKS(Covenant in force “for one week”).
Consequently, after 36 C.E., all, Jews and Gentiles, have had the same standing in God’s eyes. (Ro 11:30-32; 14:12)
"Jesus changed his mind in Matthew" is a good observation KJ. In fact a study of the Bible and some reports show that:
1- according to his own words Jesus "was sent ONLY to the lost sheep of the nation of Israel." Matthew 15:24
2- this exclusivity continues till the end times "when the son of man (that's Jesus describing himself) shall sit on the throne of his glory, ye (his 12 disciples) also shall sit upon twelve thrones, judging the TWELVE TRIBES OF ISRAEL" (Matthew 19:28).
3- the so called great commission is where, in his appearance after crucifixion, Jesus is reported as saying “go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, 20and teaching them to obey everything I have commanded you.” However, this only appears in the Gospel of Matthew 28:19-20,
4- there is no post crucifixion appearance of Jesus in the oldest manuscript, the Sinai Codex of Mark. This adds to the doubt over the so called "Great Commission" which is often quoted as justification for the deadly commitment with which Christians proselytise often sacrificing whatever it takes in the process, including their lives.
5- even if we accept the passage as it appears in Matthew, we can see from it that Jesus did not want a different set of the laws for the Gentiles. The command says, "ALL NATIONS.....teaching them TO OBEY ALL I HAVE COMMANDED" If ONLY JEWS were meant to obey these laws, then why would Jesus have instructed Jews to teach people of all nations to OBEY these laws?
6- either Jesus did not give the so called "Great Commission" or if he did then his followers decided to disobey the command of "baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:" you see, there is no evidence in any part of the NT that any of them baptised as the alleged verse commands.
7- according to Johannes Lehmann's "The Jesus Report" translated by Michael Heron and published in 1972 by Souvenir Press, London, “Paul did something that Rabbi Jesus never did and refused to do. He extended God’s promise of salvation to the Gentiles; he abolished the law of Moses, and he prevented direct access to God by introducing an intermediary.” The religion Jesus practised and taught, where righteousness is through keeping the law, became Christianity where sins are taken away by the death and resurrection of Jesus. As Hugh Joseph Schonfield, a British Bible scholar says, ‘The Pauline heresy became the foundation of Christian orthodoxy and the legitimate church was disowned as heretical.’”
If Paul’s teachings are identical to what Jesus taught in his lifetime, as Christians strongly insist, then Paul’s teachings should be redundant. By following the Bible but ignoring ALL of Paul’s writings Christians should still end up with what they believe in today. However, we know that that is just NOT true. Don’t take my word for it. Try it out for yourself if you’re a Christians.