Complex sentence: During this time, as Father Damien was teaching the Catholic faith to the people of Hawaii, he decided to aid the leper colony on the Kalaupapa Peninsula where patients with leprosy were quarantined for the mistaken belief that leprosy was highly contagious.
Split into simpler sentences: During this time, Father Damien was teaching the Catholic faith to the people of Hawaii. Damien decided to aid the leper colony on the Kalaupapa Peninsula where patients with leprosy were quarantined for the mistaken belief that leprosy was highly contagious.