I don’t understand why people find this so challenging? I guess it is because we all want to do something to earn God’s favor because then we can feel like we have a part in it. However I would ask why would Jesus breakdown the Jewish system of continual sacrifices, ritual washing, ritual diet laws, etc just to institute a new set of laws that are just as restrictive? The NT clearly teaches that the OT system was to show that it is only by loving and trusting in the Lord that we are saved because God demands perfection and nothing less.