Was European Christianity in serious decline in the early 1500’s?

No it wasn’t in decline during this period

Explanation:

Christianity wasn’t at a decline during this period. During this period the Roman Catholics were known as the forefront of Christianity before the formation of Protestant churches.

The Roman Catholic Church was held in high regard during this period and people believed that joining them as a passport to make heaven. The decline started occurring around 1600 when Protestant churches were formed .

answer; i believe that the correct answer is (chronological order);