And that is supposed to prove what?
Mat 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
I always get a chuckle when the messianics quote this passage and then fail to explain why it is that they are free to ignore all the detailed stipulations given in the Mosaic law about how Israel in the land was to keep the feasts, etc and may pick and choose the parts of the ceremonial/Levitical law that should be kept today. I guess jot and tittle really does not mean anything in your system.
Can you show exactly where in the Bible God gave commands for how to keep all these feast days under the new covenant without benefit of the jots and tittles that were given originally?
The rabbis had to invent new law to explain this to their post-AD70 followers. Can you explain why it appears messianic are doing precisely the same thing today?
Paul kept the feasts while the temple system was still in place to win his fellow Jews to Christ, not in order to find special favor with God.
19 For though I am free from all men, I have made myself a servant to all, that I might win the more; 20 and to the Jews I became as a Jew, that I might win Jews; to those who are under the law, as under the law, that I might win those who are under the law; (1 Cor. 9)
What was Paul admitting about the law when he says he became as a Jew? And what does Paul say abut those who place themselves under the law?
For as many as are of the works of the law are under the curse; for it is written, Cursed is everyone who does not continue in all things which are written in the book of the law, to do them. (Gal. 3:10)
But if you are led by the Spirit, you are not under the law. (Gal. 5:18)
You need to read all of Paul to get the right picture.
Nice of you to make up a reason for Paul's behavior. Paul and every other early Christian didn't have an "old" testament. Their bible said:
Lev 23:2 Speak unto the children of Israel, and say unto them, Concerning the feasts of the LORD, which ye shall proclaim to be holy convocations, even these are my feasts.
Lev 23:41 And ye shall keep it a feast unto the LORD seven days in the year. It shall be a statute forever in your generations: ye shall celebrate it in the seventh month.
Act 18:21 But bade them farewell, saying, I must by all means keep this feast that cometh in Jerusalem: but I will return again unto you, if God will. And he sailed from Ephesus.
Paul didn't tell his fellow Christians "I have to go evangelize in Jerusalem". He specifically said that he was going to "keep the feast".
1Co 5:8 Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.
He instructed Christians to "keep the feast".
Paul observed the holy days of Jesus Christ because Christ created HIS holy days. When Christ incarnated, he observed the holy days and Paul imitated his example:
1Co 11:1 Be ye followers of me, even as I also am of Christ.
1Co 11:2 Now I praise you, brethren, that ye remember me in all things, and keep the ordinances, as I delivered them to you.
Your explanation for Paul's behavior just doesn't match up with scripture.