Revelation 14 continues the dramatic Act that began at chapter 12. We have tried to consistently read Revelation as speaking not to individuals, but to groups and systems. Revelation is then addressed not to individual Christians, but to the Church. Revelation sees the opponents of the church not as individual peoples, but as systems (including political, religious, social, economic, entertainment) of the world that run on principles that are against God’s principles.
With these principles in mind, a couple of the key messages of Revelation 14 are against 1) those who seek to influence worldly systems through collective participation of Christians in said systems, and 2) those who would seek to gain influence of the worldly systems to promote and benefit the church. The message is that systems based upon principles of the world will never be redeemed by the collective influence of Christians. When the church collectively attempts to participate and influence worldly systems, it is the church that becomes infected with the very principles it originally set out to correct.
The very beginning of Revelation, the Seven Letters to the Seven Churches, addressed the Church. The collective message of the letters was against accommodating the Empire in order to gain and leverage her favor for the Church. Revelation 14 reiterates the message, but much more forcefully and graphically. John has already depicted the worldly powers (“those who dwell on earth”) as never repenting. The message of the three angels is not a warning to the world, but a declaration. The “good news” is not so much the proclamation of the gospel so that the world might repent, but the proclamation of judgment against the Church’s oppressors to vindicate the Church.
There is great temptation among Christians to attempt to redeem the world by working through its systems. There is also great temptation among Christians to hold up “trophies” it has “captured” from among the world in order to bolster its position and prominence. Revelation exhorts the Church to reject both temptations. That is not to say individuals cannot be in the world (remember, Revelation is not speaking to individual actions), but rather the Church must remain separate from the world.