Sound-scaping with Vocals.
Most bands would probably play an extra guitar or instrument, but often using the voice in different ways can add a completely new dimension.
If you’re going to create a pad with vocals, remember to take the pad out of the instruments.
One of the advantages of using vocal layering is that it’s really human, so it’s going to add depth to a song that an instrument can’t do, especially when you stack vocals together.
A vocal hook will encourage the congregation to pick it up, something an instrument wont usually have success with.