Before answering this question, a little explanation is in order. The Sabbath was a special day set aside as holy to God. Sabbath laws are spelled out in the Old Testament as part of the law God gave to the nation of Israel. On the Sabbaths, Jews were not allowed to do any work. The worship at the temple filled a big part of the day and the rest of the day was not free for the Jews to use however they wanted. The entire day was to be set apart to God. Sabbath days were of two kinds, the seven holy days set apart through the year- such as the Day of Atonement, Passover and Penecost- and the weekly Sabbath.
When someone talks about a responsibility to keep the Sabbath, usually he is referring to observing the weekly Sabbath. In the Bible the weekly Sabbath was always on Saturday, the seventh day of the week. This was in accord with God’s commands and reflected God’s cessation of labor after the six days of creation. In the church today many people view Sunday as a kind of Christian sabbath. Whatever the specific details of a person’s view of the proper sabbath day, the answer to the question “do I have to keep the Sabbath to be saved”, is still the same.
Sabbath keeping was not and is not necessary for salvation. The Sabbath has no relationship to salvation. This is because salvation is accomplished completely by Jesus and received by faith apart from any individual effort to secure salvation. The Bible is very clear on this point. Salvation is only by faith without any work or merit on the part of the person being save. If one believes he is saved because of faith and Jesus and personal obedience, that one is not saved. (Romans 3:28) God does not grant salvation to one who trusts Jesus and himself. God only saves those who turn away from all other means of salvation to trust only in Jesus. A person does not have to be baptized to be saved. A person does not have to take communion to be saved. A person does not have to accept the eucharist to be saved. A person does not have to attend church to be saved. A person does not have to attend mass to be saved. A person does not have to keep the Sabbath to be saved.
Some will respond that they are not teaching Sabbath keeping as necessary to get saved but keeping the Sabbath is necessary to remain saved or to show the genuineness of salvation. Again, this has no Biblical foundation. The Bible declares that salvation is accomplished and kept by Jesus. At least two entire books of the Bible, Galatians and Colossians, are written to correct the false teaching that something other than Jesus is needed to for salvation or to keep one saved. Believers are asked a piercing question in Galatians 3:3, “Having begun in the Spirit, are ye made perfect in the flesh?” Since salvation is a work of God, can a man bring God’s work to completion? Certainly not. Instead, the Christian and his salvation is complete in Jesus who is fully and perfectly God. (Colossians 2:9-10) Salvation is received by faith in Jesus. Salvation is the gift of God and is never granted for deeds done or service rendered. Either Jesus did and does everything necessary for salvation, or salvation is not of grace but of works.