The name of Nicole Kidman and Keith Urban's new baby is not a remarkable name: it's Faith. What makes it remarkable is the pairing of the new baby's name with the name of her sister, which is Sunday.
Sunday and Faith. Granted, it would be VERY DIFFICULT to come up with a sibling name for a child named Sunday, and that's one good reason not to USE a name such as Sunday. Sunday and Olivia? No. Sunday and Tuesday? No. Sunday and Genevieve? No. Sunday and June? No. Sunday and Kailey? No. Sunday and Sydney? No. Sunday and Heather? No. Sunday and Penelope? No. But I would also have said "Sunday and Faith? No."
Sunday is a highly unusual word name, reportedly inspired by Australian Sunday Reed, in a category with names such as Pilot and Apple. Faith is also a word name, but well-known and Top 100 and traditional/Puritanical, in a category with names such as Hope and Rose. The difference in style is masked by the association of the word meanings; it's easier to see with examples such as Tuesday and Faith, or Wednesday and Grace.
However, now what they have is not only a sibling set but a THEME, and so it would be EASY to come up with suggestions for the couple's third child together. For a boy: Church, Bishop, Deacon, Christian, Temple, Benediction. For a girl: Trinity, Hosanna, Epiphany, Spirit, Angel, Miracle.