The problem with the people in Amos is that they had corrupted themselves by idolatry. Their feasts were corrupt. Any kind of feast in that context is going to be condemned. I'm sure there are feats days even today that God hates.
It’s not the works of the law God loves,
Ro 9:32 33 Wherefore? Because they sought it not by faith, but as it were by the works of the law. For they stumbled at that stumblingstone; As it is written, Behold, I lay in Sion a stumblingstone and rock of offence: and whosoever believeth on him shall not be ashamed.
I don't consider celebrating God's Holy Days a work. It's a pleasure and a blessing. Neither did Paul...as he also kept them:
1Co 5:8 Therefore let us keep the feast; not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.
I know you don't, and neither did the scribes and Pharisees and those who had the millstones about their neck, and that's why they didn't want the change Christ offered them, they preferred the devil they knew.
1Co 5:8 Therefore let us keep the feast; not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.
Paul wasn't keeping this or any Jewish feast, and he never recommended that any Gentile keep them either.
In Exodus 12, the Paschal lamb was slain every year to cleanse out the leaven of sin. Jesus died once for all, and the yearly sacrifice was done away with.
Today, it’s a daily cleansing from within, and it’s up to each one of us to cleanse his own heart, and not to do it as ancient Israel did, which was strictly a physical cleansing of the leaven from the dough, it was a type, but today we keep it from within.
V-8 - but with the unleavened bread of sincerity and truth. Paul gave the Gentiles the true meaning of the unleavened bread. It’s no longer bread with out the leavening, but its every man filled with sincerity and truth.
1 Cor 8 is not about a Jewish feast, it’s about fornication in the church. Paul used the leavening to make a point that it couldn’t be left in the church or everyone there would become effected, and the feast of UB was a good example of how sin would grow.
As far as I can tell, there is no Jewish feast coming up when this letter was written to the Corinthians, so it’s not likely that's what influenced Paul’s analogy.
The only time Paul said he had to be in Jerusalem for a feast was in…..
Acts 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.
Notice Paul said nothing about the Gentiles or any of the other Christians going along with him, and the reason he had to go was because he had taken a vow, and it was to end at this feast, and it was probably Pentecost.
Now notice Galatians 1:18 Then after three years I went up to Jerusalem to see Peter, and abode with him fifteen days.
Also Galatians 1:18 Then fourteen years after I went up again to Jerusalem with Barnabas, and took Titus with me also.
For a Jew who you claim attended all the Jewish feast, here are 17 years that Paul told us he never went up to Jerusalem period, so he certainly wasn’t attending the many yearly feast that had to be kept in Jerusalem.
JH :-)