Commentaries:
Symbolically, adultery is used to express unfaithfulness to God, and we can easily see this in Israel's idolatry. God is represented as the husband of His people. Ezekiel 16:15-59 gives a graphic description of Israel's spiritual adultery, and Hosea 1:1-2 shows the same symbolism in Hosea's marriage. We can fall into spiritual adultery by relying on the world and its false teaching rather than God.
Martin G. Collins
The Seventh Commandment
Our salvation hinges on a lifetime of repentance from dead works and overcoming in faith. Thus, we are counseled before baptism to be sure we have counted the cost before we take on the awesome opportunity of eternal life. Once we take hold of the plow, we cannot turn back.
Martin G. Collins
Basic Doctrines: Repentance
The church at Thyatira is guilty of fornication. Spiritually fornication is one of God's terms for being "mixed up with the world." Fornication is something that one should never do, let alone when one is supposed to be in a relationship with another. Fornication represents idolatry'faithlessness to a relationship.
John W. Ritenbaugh
What Is the Work of God Now? (Part Four)
Consider that this is Christ's message to His church just before the end, and this is what is most important for His people as we approach the end. Doctrine is mentioned seven times. Is that interesting in light of the times in which we live? We are seeing a major part of the church going haywire on doctrine! Is there something in the letter to Thyatira that mentions things that are happening in that group?
The letters contain at least eleven warnings to these seven churches but also at least twelve promises. Christ mentions faith, patience, conduct, and doctrine. But the two greatest, related concerns for His church at the end are works (Revelation 2:2,9,13,19; 3:1,8, 15) and overcoming (Revelation 2:7,11,17,26; 3:5,12,21).
Today, an awful lot of people are interested in church government at this time. It is not even mentioned by Christ! There are people who are interested in rituals, sacraments, and ceremonies, of which would be things like baptism or the Passover. But nothing in the seven letters alludes to these things. Nor is there anything in them about preaching the gospel around the world. These things have their place, but what we see is Christ's concern with doctrine, conduct, warnings to repent, and promises of reward.
Now these things that are not mentioned are less important than faith, repentance, and holiness, all of which directly impact on doctrine, conduct, and receiving the promises. All of these are bracketed between His statements about works and overcoming.
John W. Ritenbaugh
Revelation 2-3 and Works