Thomas Tallis was a man who lived, composed, and survived through four very serious regime changes in 16th century England and its National Church Identity. The pendulum swung from Catholic to Protestant to Catholic, and back to Protestant again, and each era brought sweeping changes and dangers for what was allowed concerning Latin, composition and composers.
It was probably enough to drive Tallis and Handel to drink.
This simple and beautiful piece, from The English Anthems, is a particular favorite of mine and obviously taken from scripture, quoting John 14: 15-17.
Tallis was born a Roman Catholic and one his most famous compositions, the 40-voice Spem in alium, alludes to a strong allegiance to Roman Catholicism