Complex sentence: Christians regard the foundational principle of the lifelong union of a man and a woman to have been first articulated biblically in, and reaffirmed by Jesus in and, and by the Apostle Paul in.
Split into simpler sentences: Christians regard the foundational principle of the lifelong union of a man and a woman to have been first articulated biblically in. It was reaffirmed by Jesus in and and by the Apostle Paul in.