Faith of our fathers, Mary’s prayersThe argument could be made that we should have nothing to do with these heretical hymns but it seems to be a wiser choice to recognize the quality of the hymn while editing it to improve the theological accuracy. If our hymns depended upon the orthodoxy of the composer we would constantly be left in doubt as to what hymns we could sing, wondering exactly how orthodox someone must be in order for us to sing their hymns. Many "Christian songs" aren't worthy of correction but many others are.
Shall win our country back to Thee;
And through the truth that comes from God,
England shall then indeed be free.
In some cases unfortunately the strong and clear doctrinal statements in hymns are corrupted when they make their way into particular hymnal. Liberal, mainline Protestantism often does this. I even came across an old Baptist hymnal that omitted the words "God in three persons, blessed Trinity" from "Holy, Holy, Holy" and replaced it with something else. In an attempt to have a repeating chorus many hymnals have removed the references to the crucifixion in "What Child is This?"
Isaac Watts wrote a number of well-known hymns such as "Joy to the World." What many people are not aware of are the heretical views of Isaac Watts. He held to a heretical Christology in which "the human soul of Christ had been created anterior to the creation of the world, and united to the divine principle in the Godhead known as the Sophia or Logos (only a short step from Arianism, and with some affinity to Sabellianism); and that the personality of the Holy Ghost was figurative rather than proper or literal." He also held to a rather strange form of premillenialism. Isaac Watts wrote his hymns at a time when Calvinists would not allow man-made hymns. In order for his hymns to be accepted, Watts published some pretty extreme paraphrases of Psalms. He would replace Israel with Britain based on his eschatological views. "Joy to the World" is half of his paraphrase of Psalm 98. The reign of Christ in "Joy to the World" as originally intended by Watts was a literal millennial reign. Yet, there is nothing heretical about the words of "Joy to the World" in themselves. In fact, when viewed from an orthodox lens it does a great job of combining both the Nativity of Christ and the second coming of Christ