Before we attempt to answer your specific question, let’s look at the passage in Isaiah that you are obviously referring to. It is found in Isaiah 58:13-14, “If you turn away your foot from the Sabbath, for DOING YOUR OWN PLEASURE on My holy day, and call the Sabbath a delight, the holy day of the LORD honorable, and shall honor Him, NOT DOING YOUR OWN WAYS, NOR FINDING YOUR OWN PLEASURE, NOR SPEAKING YOUR OWN WORDS, then you shall delight yourself in the LORD; and I will cause you to ride on the high hills of the earth, and feed you with the heritage of Jacob your father. The mouth of the LORD has spoken” (NKJV).

First of all, who is God speaking to in this passage? He is speaking to His earthly people Israel, for they were the people who were given the Ten Commandments which included the commandment, “Remember the Sabbath Day to keep it holy” (Exodus 20:8). This day was to be set aside for worshipping God and serving Him. They were to observe this day to show that they had a special relationship with God and if they didn’t observe it as He commanded, they could be put to death. In Exodus 31:13-15 we read, “Speak also to the children of Israel, saying: ‘Surely My Sabbaths you shall keep, for it is a sign between Me and you throughout your generations, that you may know that I am the LORD who sanctifies you. You shall keep the Sabbath, therefore, for it is holy to you. Everyone who profanes it shall surely be put to death; for whoever does any work on it, that person shall be cut off from among his people. Work shall be done for six days, but the seventh is the Sabbath of rest, holy to the LORD. Whoever does any work on the Sabbath day, he shall surely be put to death.”

So, the children of Israel were not only to abstain from having any “personal pleasure” on the Sabbath Day, they were also to refrain from “personal gain” by working. This day was to be wholly committed to the Lord, either by worshipping Him or by serving Him by “serving others” by caring for “the oppressed, the hungry, the poor, and the naked” (see verses 6-7 of Isaiah 58).

Believers today, who make up “the church of God,” are NOT under the law of Moses, but under the grace of our Lord Jesus Christ. In John 1:17 and Romans 6:14 we read, “For the law was given through Moses, but grace and truth came by Jesus Christ….you are not under law but under grace.” This means that the law of “observing the Sabbath Day” does not apply to us. Some may not see this and judge us for not “keeping the Sabbath.” The apostle Paul addressed this issue in Colossians 2:16, “So let no one judge you in food or drink, or regarding a festival or a new moon or SABBATHS.” There will be those who say, “Christians don’t have to ‘keep the Sabbath,’ but the Lord’s Day (Sunday) is our day of rest in which we worship the Lord and serve Him by serving others.” They may also go on to say, “On the Lord’s Day we should refrain from all work and personal pleasure.” I do agree that the Lord has, in His sovereignty, given us the “Lord’s Day” so we can come together to worship Him in the breaking of bread and to minister to one another (see Acts 20:7), but it is NOT a day to be OBSERVED IN A LEGAL WAY and it is certainly NOT PUNISHABLE BY DEATH if we don’t follow the restrictions that were given to the Jews.

Regarding your question about married couples, perhaps we should ask ourselves, “Would it be wrong for a Christian married couple to engage in sex on the Lord’s Day?” My personal opinion is that it would NOT be wrong if it doesn’t distract you from worshipping the Lord and serving Him. Let’s remember that marriage is a holy institution that is sacred to God (just as the Sabbath Day was sacred to God). In Hebrews 13:4 we read, “Marriage is honorable among all, and the bed undefiled.” Sex between a husband and wife should NOT be looked upon as sinful or even as a selfish pleasure. Sex SHOULD be a way of giving one’s spouse pleasure and in that context you are serving others. This is addressed by the apostle Paul in 1st Corinthians 7:3-5, “Let the husband render to his wife the affection due her, and likewise also the wife to her husband. The wife does not have authority over her own body, but the husband does. And likewise the husband does not have authority over his own body, but the wife does. Do not deprive one another except with consent for a time, that you may give yourselves to fasting and prayer; and come together again so that Satan does not tempt you because of your lack of self-control.” Some may say, “But surely Paul’s words don’t apply on the Lord’s Day.” To that I would say, “If Paul had thought married couples should abtain from having sex every Lord’s Day, he would have said so.” (288.9) (DO)