Is it in observance of God’s rest and Commandment?

From the accounts of Moses in Genesis 2, we read that God made the seventh day holy as He rested after the six days work.

God blessed the seventh day, and made it holy because he rested it from all His works which God had created and made (Genesis 2:2)

And as the people of Israel come out of Egypt to the promised Land, the observance of making the seventh day as holy and rest day is God's command for His people to observe forever.

It is a sign between me and the people of Israel forever; for in six days the Lord made heaven and earth, and on the seventh day He rested and was refreshed. (Exodus 16:30)

It is clear that God's people must observe making the seventh day holy.

Are Christians obliged to observe the commandment of resting literally on the Sabbath day?

The people of God in the Old Testament were mandated to enter into God's rest by observing the rest day every seventh day of the week. It was the time when they are to stop from all their work. They were to rest on seventh day.

However, in the New Testament, there is much greater rest which is provided by God. It is what most commonly called as the "Believers' Rest". We read in Hebrews 3:11-14:

11“As I swore in my wrath, ‘They will not enter into my rest!”. 12Beware, brothers, lest perhaps there be in any one of you an evil heart of unbelief, in falling away from the Living God; 13but exhort one another day by day, so long as it is called “today”, lest any one of you be hardened by the deceitfulness of sin. 14For we have become partakers of Christ, if we hold fast the beginning of our confidence firm to the end;

Christian's Sunday fellowship or meeting up with one another is not a replacement of Israel’s obedience to God’s command of keeping the Sabbath Day Holy.

Meeting on a Sunday is an observance of celebration of Jesus Christ's resurrection which can be read in Luke 24. It is the Day when the Lord has risen from the dead (v1-8), it is the day when the Apostles and His disciples were meeting together (v9). It is the day when the Lord celebrated the breaking of bread which He gave to his disciples (v.30)

"It is undeniable that the Sabbath day is Holy.

However, with the Lord Jesus Christ' fulfillment of the Law,

God's rest has been given to His people."

6 Seeing therefore it remains that some should enter therein, and they to whom the good news was before preached failed to enter in because of disobedience, 7 he again defines a certain day, today, saying through David so long a time afterward (just as has been said), "Today if you will hear his voice, Don't harden your hearts." 8 For if Joshua had given them rest, he would not have spoken afterward of another day. 9 There remains therefore a Sabbath rest for the people of God. 10 For he who has entered into his rest has himself also rested from his works, as God did from his. 11 Let us therefore give diligence to enter into that rest, lest anyone fall after the same example of disobedience. (Hebrews 4:6-11)

The writer of the Hebrews has emphasized the coming of another day of rest, not the kind of rest on a specific day as in the time of Joshua. Christians are called to be diligent in entering into that coming rests.

16 Therefore, no one is to act as your judge in regard to food and drink, or in respect to a festival or a new moon, or a Sabbath day—(Colossians 2:16)

Apostle Paul addressed this letter to the Christians in Colossae to address the stressor campaign of literally complying with the Laws of Moses, when the promised rest of the Lord has come through the Lord Jesus Christ.

The observance of Sabbath day was for Israelites to obey according to Mosaic Law. However, every person, prior to Christ, has always been disobedient and could not fulfill the observance of the Sabbath. That is why, it only with Jesus Christ to which this law was and is fulfilled as what the Lord has said in Matthew 5:17

“Do not presume that I came to abolish the Law or the Prophets; I did not come to abolish, but to fulfill.

Christians Gather every first day of the week.

24 Let us consider how to provoke one another to love and good works, 25 not forsaking our own assembling together, as the custom of some is, but exhorting one another; and so much the more, as you see the Day approaching. 26 For if we sin willfully after we have received the knowledge of the truth, there remains no more a sacrifice for sins, 27 but a certain fearful expectation of judgment, and a fierceness of fire which will devour the adversaries. 28 A man who disregards Moses' law dies without compassion on the word of two or three witnesses. 29 How much worse punishment, do you think, will he be judged worthy of, who has trodden under foot the Son of God, and has counted the blood of the covenant with which he was sanctified an unholy thing, and has insulted the Spirit of grace? (Hebrews 10:24-29)

The observance of Sabbath day is for Israel to observe, not for Christians, especially Gentile Christians. Christians becoming co-heirs with Christ is on being able to come into God’s promised rest in His presence, not in the strict observance of Sabbath day.

"Accessing rest in God’s presence is no longer restricted to Sabbath day,

but “as long as it is called today”.

However, it does not mean that Christian would denounce that the Sabbath day is no longer Holy, it is Holy because God intended and commanded it to be.

Sunday fellowship of Christians has reasons but are not limited to the following:

a. Opportunity to provoke one another to love and good works.

b. To hear/share the words of God.

c. To sing to one another with psalms, hymns, and spiritual songs.

d. To bring tithes for God and the offering for the household of faith.

e. To persevere in meeting with one another, not forsaking it’s importance.

f. And many more.

Again, Hebrews 4:11 commanded Christians:

Let us therefore give diligence to enter into that rest, lest anyone fall after the same example of disobedience.

Therefore, as Christians, we prioritize coming to God's promised and provided rest through the Lord Jesus Christ, as long as it is called today, but never deny the Sabbath as Holy day.