The Lord’s day (as distinguished from the day of the Lord) is Sunday. The term Lord’s day is used only once in Scripture. Revelation 1:10 says, “I was in the Spirit on the Lord’s day, and I heard behind me a loud voice like a trumpet.” Since the apostle John does not elaborate on the meaning of “Lord’s day,” we can assume that his target audience, first-century Christians, were already familiar with the expression.
Some have assumed that the Lord’s day is the New Testament equivalent of the Sabbath. The Sabbath day was instituted by God for the nation of Israel to commemorate His deliverance of them from Egypt (Deuteronomy 5:15). Sabbath began Friday at sunset and ended Saturday at sunset and was to be a day of complete rest from all labor, symbolic of the Creator’s resting on the seventh day (Genesis 2:2–3; Exodus 20:11; 23:12). The Sabbath was a special sign to the Israelites that they had been set apart as followers of the most High God. Their keeping of the Sabbath would help distinguish them from the nations around them. However, nowhere in Scripture is the Sabbath ever referred to as the Lord’s day. The term Sabbath was still in use within the Jewish community in New Testament times and is referred to as such by Jesus and the apostles (Matthew 12:5; John 7:23; Colossians 2:16).
Sunday was the day that Jesus Christ rose from the dead, an act that forever separated Christianity from any other religion (John 20:1). Since that time, believers have gathered on the first day of the week to celebrate His victory over sin and death (Acts 20:7; 1 Corinthians 16:2). Even though the Sabbath day was designated by God as a holy day, Jesus demonstrated that He was Lord over the Sabbath (Matthew 12:8). Jesus stated that He had come not to abolish but to fulfill the whole Law. Rule-keeping could not justify anyone; only through Jesus could sinful humanity be declared righteous (Romans 3:28). Paul echoes this truth in Colossians 2:16–17 when he writes, “Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. These are a shadow of the things that were to come; the reality, however, is found in Christ.”
The Lord’s day is typically thought of as Sunday, but it is not a direct counterpart to the Jewish Sabbath—in other words, Sunday is not the “Christian Sabbath.” Although we should set aside a day for rest and honoring the Lord who died and rose for us, we are not under the Law (Romans 6:14–15). As born-again followers of Jesus, we are free to worship Him on any day that our conscience determines. Romans 14 gives clear explanation of how Christians are to navigate those subtle gray areas of discipleship. Verses 4 and 5 say, “One person considers one day more sacred than another; another considers every day alike. Each of them should be fully convinced in their own mind. Whoever regards one day as special does so to the Lord. Whoever eats meat does so to the Lord, for they give thanks to God; and whoever abstains does so to the Lord and gives thanks to God.”
Some Messianic Jews want to continue regarding the Sabbath day as holy because of their Jewish heritage. Some Gentile Christians join their Jewish brothers and sisters in keeping the Sabbath as a way to honor God. Worshiping God on the Sabbath is acceptable—again, the day of the week is not the most important issue—but the heart motivation behind that choice is crucial. If legalism or law-keeping motivates the choice to observe the Sabbath, then that choice is not made from a right heart condition (Galatians 5:4). When our hearts are pure before the Lord, we are free to worship Him on Saturday (the Sabbath) or Sunday (the Lord’s day). God is equally pleased with both.
Jesus warned against legalism when He quoted Isaiah the prophet: “These people honor me with their lips, but their hearts are far from me. They worship me in vain; their teachings are merely human rules” (Matthew 15:8–9; cf. Isaiah 29:13). God is not interested in our keeping of rituals, rules, or requirements. He wants hearts that are on fire with His love and grace on the Sabbath, on the Lord’s day, and on every other day (Hebrews 12:28–29; Psalm 51:15–17).