When Leviticus condemns shellfish, pork and mixed fibre clothes as abominations, etc, and Jesus in the NT says he doesn‘t want to change ‘one word‘ of the OT, was he talking about how they *used* to understand it, not its current form. People in bible times had never enjoyed a Lobster Thermador, or had a lovely snug polyester-blend sweater-vest, or eaten a bacon sandwich.In the old days, oysters contained pure evil and were a threat to their tribes. Pagans at that time worshiped prawns, they were just talking about eating pork pies in the temple in order to worship Baal. Sodom and Gomorrah was destroyed for forcing-feeding each other bacon sandwiches, not consensual and loving BLT‘s covered in tomato sauce and mayo. mmmm
When jesus was crucified, many of the necessary rituals that had to be preformed in the OT were no longer needed due to jesus being the ultimate sacrificial lamb, to that extent, many of the OT laws that served merely to cleanse or keep clean weren't an issue anymore. So to my understanding, pork and shellfish should be okay (but I'm also not an expert).
The Bible: Try reading it. Act 10:11 KJV - And saw heaven opened, and a certain vessel descending unto him, as it had been a great sheet knit at the four corners, and let down to the earth: Act 10:12 KJV - Wherein were all manner of fourfooted beasts of the earth, and wild beasts, and creeping things, and fowls of the air. Act 10:13 KJV - And there came a voice to him, Rise, Peter; kill, and eat. Act 10:14 KJV - But Peter said, Not so, Lord; for I have never eaten any thing that is common or unclean. Act 10:15 KJV - And the voice [spake] unto him again the second time, What God hath cleansed, [that] call not thou common. Act 10:16 KJV - This was done thrice: and the vessel was received up again into heaven.
The shellfish are ok to eat, but I would not eat the mixfibre cloth was I you.
