31/05/2026
Adultery of the heart
Adultery is not only an outward physical act, but also something that begins in the heart and mind. According to the teaching of Jesus Christ, sinful desire itself can become spiritual adultery when it is entertained and nurtured within the heart.
In Matthew 5:27–28, Jesus teaches that anyone who looks at another person with lust has already committed adultery in the heart. This reveals that sin begins internally before it appears externally. God sees not only outward actions, but also the thoughts, motives, and desires hidden within a person. Lustful thoughts, when accepted and developed, can eventually lead to sinful actions. Therefore, believers are called not only to avoid outward sin, but also to pursue purity of heart. Through prayer, fasting, obedience to God, and the help of the Holy Spirit, sinful nature can gradually be removed. Spiritual growth is a process, and believers should not become discouraged when they are sincerely struggling against sin.
The passage also teaches an important distinction: a sudden tempting thought is not the same as willingly embracing and cultivating sinful imagination. God looks at the attitude of the heart and whether a person resists temptation or welcomes it. When believers repent quickly, continue fighting against sin, and seek God sincerely, He gives grace and strength to help them overcome and grow in holiness.
The Bible often likens the relationship between Israel and God to the relationship between a father and his child, but sometimes it likens it to the relationship between a husband and a wife. Here it is like the relationship between a husband and a wife who have vowed to love each other with all his/her heart. Just as a husband and wife promise to love and remain faithful to one another, God desires faithful love and devotion from His people. In the Old Testament, the people of Israel repeatedly turned away from God and worshiped idols, which the Bible describes as spiritual adultery. Even though they knew God and experienced His works, they forsook Him for false gods and worldly desires.
In the New Testament, believers are spiritually called the bride of Jesus Christ. Therefore, if believers claim to love God and know spiritual truth but still cling to worldly sin and compromise with untruth, it is considered spiritual adultery.
The message calls believers to remain faithful, pure, and devoted to God alone. Then, how are spiritual idolatry in the second commandment and the spiritual adultery in the 7th commandment different from each other? Spiritual idolatry happens when a person, especially someone with weak or immature faith, loves worldly things more than God. This can include loving money, fame, family, or worldly desires above God. Spiritual adultery, however, is considered more serious because it happens after a person has already experienced God’s grace, knows the truth, and has faith, yet still turns back to worldly darkness and forsakes God’s love.
The passage teaches that spiritual adultery is like being unfaithful to God after already entering into a relationship with Him. The core difference comes down to what you know and the choice you make based on that knowledge. It is a shift from ignorance to intentional betrayal. The passage gives a serious warning about the danger of spiritual adultery, describing it as even more severe than physical adultery. Drawing from James 4:4, it teaches that friendship with the sinful values of the world places a person in hostility toward God. When believers who know God’s grace continually choose worldly compromise over faithfulness to Him, they become spiritually unfaithful and distance themselves from God. The passage warns that when believers continually ignore conviction and persist in spiritual adultery, they may gradually become spiritually hardened losing sensitivity to the Holy Spirit, experiencing unanswered prayers, drifting deeper into worldly corruption and sinful behavior, and ultimately placing themselves on a dangerous path of spiritual separation from God, described as “crucifying Jesus Christ all over again.” Referring to 1 Corinthians 3:16–17, the passage reminds believers that their bodies are temples of the Holy Spirit and therefore must be kept holy. Christians are called to reject both physical immorality and spiritual compromise, pursuing purity, truth, and wholehearted devotion to God so they may remain faithful and spiritually prepared as the bride of Christ.