Why are Messianic Judaizers and Other Sabbatarians Hypocrites?
Not one tittle of the law will pass till all these things are finished so the laws of ancient Israel are still in place. They do not go away. What things? Till Jesus returns and reigns 1000 years on earth so not till the completion of the 1000 year reign. After the 1000 year reign is the New City and New Earth and at that time rewards are also done away in contrast to the law.
The NT says let no man judge you for what days to keep. So if a Messianic Judaizer comes up to you and says you are not keeping the Sabbath, judge him and tell him, God says, Let no man judge you what days to keep. Moreover, there is no such thing as a Christian Sabbath. The Saturday Sabbath was for a covenant with Israel and God to indicate they were the chosen people, that is to say, chosen to bring in the Messiah through blood line.
The Sabbath in ancient Israel is now fulfilled in Jesus giving us the Holy Spirit who rests in us (the saved) every day of the week as the veil is rent. What about the 7 feasts? The first four are fulfilled. The last 3 are yet to be fulfilled when Jesus returns, but you need not keep them because they were given to ancient Israel (not the Israel today). They are nonetheless a rehearsal of what is to come so do appreciate their meaning. The true Jew is a Christian now. Israel today should not be keeping feasts or sacrifices. Even so, God has Israel as a nation in view to be the center of all nations from where Jesus will reign on earth in the 3rd Temple.
But do we still put people to death for many different sins? No, of course not, because we must distinguish between the OT sense of a particular law and the NT sense. The NT sense is full of grace so no stoning. Jesus forgave the adulteress. This is affected by the mercy and grace of the Father giving the Son. The law shows us our sins and give sin strength as man becomes aware he keeps breaking God's laws. Christians can't even keep the conduct of Matthew 5-7 (Sermon on the Mount) but through God's grace overtime we will. The spiritual Christian will receive reward for doing so. The carnal Christian though cannot lose eternal life will lose the reward of returning with Christ to reign 1000 years.
In conclusion, the NT sense is full of grace, no longer living by the law, for surely we would die by that law since no man can keep it. In terms of your Messianic Judaizer or 7th Day Adventists encounters, realize they according to their own law should be put to death, because I assure you at one time or another they have done some sort of work on their self-imposed Sabbath. They are hypocrites.
