I love your Christmas music. Your voice seems tailored to fit well with traditional religious carols. However, when you changed the words to "What Child Is This?" you not only lost the theological meaning, you lost much of the human interest, as well.
Singing "Raise, raise, the song on high, his mother sings a lull-a-bye" lacks the emotional depth of "Raise, raise the song on high, the Virgin sings a lull-a-bye." After all, "his mother" could refer to any baby born on December 25th.
If the content of the religious carols as written bothers you enough that you change the lyrics, maybe you should not be singing them in the first place.