Notice how in 18 - it points towards the Torah being Prophetic... "Till all is FULFILLED" - this is a prophetic statement..... Every single ordinance and command has A PURPOSE.... My firm belief is that we have not encountered the REASON each one of these has been issued yet.... and that's why some ordinances still don't really make sense....
Think of how many plagues and diseases were STOPPED when we went back to God's law.... For example... Look at modern food safety and preparation laws... They mirror Torah for Ceremonial washing, ceremonial food preparation, handling unclean things that fall in pots, etc....
Notice now, in 19
"Whoever therefore breaks one of the least of these commandments, and teaches men so, shall be called least in the kingdom of heaven"
Notice It does not declare you will be CAST OUT of the Kingdom... It says you will be declared LEAST in the Kingdom.... that means you can still be ADMITTED to the Kingdom of Heaven as a "Lawbreaker"....
Now.. On to Paul's comments about the Law being a Tutor.....
I have kids.... What do you teach a 3 year old kid about Knives... DO NOT TOUCH! Why? you know EXACTLY what will happen... The kid is NOT ready - and the kid may kill themself or end up in the hospital.....
Now... as the kid starts to get older - you start TEACHING them how to use knives.... There will be some "Accidents" - but they happen in a controlled environment.... Finally - when the kid is grown - THEY can use the knives on their own....
Now... Think about food purity.... People were NOT ready to understand food purity.... so God gave the Israelites a set of rules that would greatly reduce trouble.... The laws Are still TRUE.. If you follow them - YOU WILL LIVE.... but there was no explanation of the what's and why's... Man wasn't ready.... "Go ahead and eat anything" resulted in CALAMITY among the Gentiles - INCLUDING CHRISTIANS - with all sorts of issues with food poisoning, blood diseases, plagues, and parasites.... and BECAUSE of following God's law - those things did NOT happen among the Jews like they did among the Gentiles...
thanks...