Complex sentence: Giovan Battista Bernareggi's son pledged then to restore it and provide its furnishing, as the church was "important to the spiritual needs" of the inhabitants of Baraggia.
Split into simpler sentences: Giovan Battista Bernareggi's son pledged to restore the church and provide its furnishing. This was because the church was "important to the spiritual needs" of the inhabitants of Baraggia.