In the realm of denominational, man-made religion, no doctrinal truth or biblical practice is untouchable.  When ordinary men and women are given the authority to establish what is preached and practiced by God’s people (or those viewed as God’s people), instead of men guided by the Holy Spirit, namely the apostles of Christ, anything goes.

In the last several years, we have seen this come to fruition with the decision of denominational churches to change their day of worship from Sunday to Saturday.  As Christians, we must always earnestly contend for the faith by insisting that the day of worship for God’s people remains the God-appointed first day of the week, not the seventh.

The New Testament is clear about the commanded day of worship being Sunday, the first day of the week.  The church in the first century was commanded to commemorate the death of our Lord.

1 Corinthians 11:23–26 (ESV)
²³ For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, ²⁴ and when he had given thanks, he broke it, and said, “This is my body, which is for you. Do this in remembrance of me.” ²⁵ In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” ²⁶ For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until he comes.

When were they to do this?  On the first day of the week.  How do we know it?  Because that is when they came together to worship God as local churches. Acts 20:7 (ESV)

⁷ On the first day of the week, when we were gathered together to break bread, Paul talked with them, intending to depart on the next day, and he prolonged his speech until midnight.

The first-century church had a specific day when they were to come together to worship God.  We know this because the writer of Hebrews commanded saints not to forsake this gathering.

Hebrews 10:25 (NKJV)
²⁵ Not forsaking the assembling of ourselves together, as is the manner of some, but exhorting one another, and so much the more as you see the Day approaching.

Since Paul and the saints at Troas came together on the first day of the week, we know that it was the appointed time for worship.  This is corroborated by Paul’s instructions to the saints at Corinth concerning when they were to give to the Lord.

1 Corinthians 16:1–2 (NKJV)
¹ Now concerning the collection for the saints, as I have given orders to the churches of Galatia, so you must do also: ² On the first day of the week let each one of you lay something aside, storing up as he may prosper, that there be no collections when I come.

Why did Paul tell these saints to lay something aside on the first day of the week?  It was because he knew that was the day they would come together to worship.  This is what the church did under apostolic guidance.  All the evidence that we have from both the bible itself, as well as from extra-biblical writings from the early second century, tell us that the day of the Lord was Sunday.

Since the apostles, who were ambassadors for Christ, authorized this, no man or group of people today has the authority to change it.  Remember, we must do all things according to the pattern (Hebrews 8:5), and gathering to worship God on the first day of the week, including observing the Lord’s Supper and laying something aside monetarily, is undeniably a part of that pattern, and, therefore, a part of the faith for which we must contend.

As you wind down for the night, think about these things.