Which traditional Christian doctrine is only explicitly taught in a passage most likely not originally in the New Testament?

Question

Quizplus · Accepted Answer

The doctrine of the Trinity, while a foundational concept in most branches of Christianity, is not explicitly outlined in the original texts of the New Testament. The closest explicit reference to the Trinity is found in the Comma Johanneum (1 John 5:7-8), which is widely considered by scholars to be a later addition and not part of the original New Testament manuscripts.

Which Traditional Christian Doctrine Is Only Explicitly Taught in a Passage