God is especially displeased with idolatry; He is the one true God, and we should be careful not to give credit to any other god or power. Right after the sin of golden calf, God has Moshe tell them to keep Shabbat. That is the day that God rested after He created everything. Honoring Shabbat says that we believe that God is the creator. The commandment about keeping the 7th day is associated with God resting on the 7th day. Those that keep the day of rest on the pagan day of the sun god think they are honoring God. Deuteronomy 18:9,12 "You shall not learn to follow the abominations of those nations." Verse 12 says, "For all who do these things are an abomination to the LORD." I am just quoting what the Bible says. Read your Bible. 

There is another important issue to consider. Exodus 31:14 NKJV says about Shabbat, "Whoever does any work on it, that person shall be cut off from among his people." This could be the reason that people were to be put to death for not keeping the Sabbath, or since being put to death is already mentioned, this scripture could refer to being "cut off" for eternity. Genesis 35:29 NKJV says, "So Isaac breathed his last and died, and was gathered to his people." A dead person cannot be gathered to their people if they are dead. So, this must be an idiom for joining those who would live again in God's eternal kingdom. Moshe, Aaron, Jacob, Ishmael, Isaac, and Abraham were gathered to their people when they died. So, they will be in the future eternal kingdom along with all true and faithful believers from all of time. 

Those who are "cut off" from their people then would suggest that these people will not have eternal life in God's future kingdom. In the case of the person who works on Shabbat, they will not be in God's future kingdom. While God is an all-knowing and just God, this scripture should be a serious warning to consider. If this is the right way to interpret this scripture, those who are keeping the day of rest on the day of the pagan sun god will not be in God's future kingdom. I am committed to doing all that God commands us to do and this is not an issue for me because I keep God's weekly 7th day of rest, but it is an issue for the many people who continue to keep Sunday as a day of rest, the day of the pagan god Mithras. If you are being hard hearted towards which day is God's day of rest which commemorates creation, I hope you will reconsider and be more open to following what God says to do and to His commandments.