marshmallow:
I think it depends, there are some great Hyms that were written by those from Protestant traditions that are no problem for Catholic Liturgy. Many of the hyms from the Anglican tradition [including those written by Wesley] are theologically in line with Catholic Doctrine and are appropriate for Litugry. Some of the hyms from the Lutheran Tradition would also be appropriate.
Modern Protestant music from the non-Liturgical Protestant traditions should not be used in Catholic Liturgy, in my view.
Be Thou my Vision, O Lord of my heart;
Naught be all else to me, save that Thou art.
Thou my best Thought, by day or by night,
Waking or sleeping, Thy presence my light.
Be Thou my Wisdom, and Thou my true Word;
I ever with Thee and Thou with me, Lord;
Thou my great Father, I Thy true son;
Thou in me dwelling, and I with Thee one.
Be Thou my battle Shield, Sword for the fight;
Be Thou my Dignity, Thou my Delight;
Thou my soul’s Shelter, Thou my high Tower:
Raise Thou me heavenward, O Power of my power.
Riches I heed not, nor man’s empty praise,
Thou mine Inheritance, now and always:
Thou and Thou only, first in my heart,
High King of Heaven, my Treasure Thou art.
High King of Heaven, my victory won,
May I reach Heaven’s joys, O bright Heaven’s Sun!
Heart of my own heart, whatever befall,
Still be my Vision, O Ruler of all.