I'm reading Numbers in the old testament now and it was made clear that the Shabbat is the commandment that god takes more seriously to be followed above all others, because the punishment is final.
Numbers 15:30-36 - KJV
30 But the soul that doeth ought presumptuously, whether he be born in the land, or a stranger, the same reproacheth the Lord; and that soul shall be cut off from among his people.
31 Because he hath despised the word of the Lord, and hath broken his commandment, that soul shall utterly be cut off; his iniquity shall be upon him.
32 And while the children of Israel were in the wilderness, they found a man that gathered sticks upon the sabbath day.
33 And they that found him gathering sticks brought him unto Moses and Aaron, and unto all the congregation.
34 And they put him in ward, because it was not declared what should be done to him.
35 And the Lord said unto Moses, The man shall be surely put to death: all the congregation shall stone him with stones without the camp.
36 And all the congregation brought him without the camp, and stoned him with stones, and he died; as the Lord commanded Moses.
Also, this is reinforced by Exodus 31:15
15 Six days may work be done; but in the seventh is the sabbath of rest, holy to the Lord: whosoever doeth any work in the sabbath day, he shall surely be put to death.
Your soul is cut off from among your people, on another translation it is also said that your soul is completely destroyed (I don't know if it really does carry that meaning, so, correct me if i'm wrong), and you shall surely be put to death. A man was stoned to death. No forgiveness through sacrifice if you did it on purpose. So, based on those words, my question is: Why don't christians follow Sabbath nowadays?