Final answer:
Lutherans believe that the Bible alone is the source of truth, while Catholics believe that the Bible and tradition are sources of truth.
Step-by-step explanation:
The belief that the Bible alone is the source of truth is a key belief in Lutheranism. Martin Luther, the founder of Lutheranism, emphasized the importance of scripture and rejected the authority of the Catholic Church. He believed that individuals should have direct access to the Bible and be able to interpret it for themselves, without the need for priests to interpret it on their behalf.
On the other hand, the belief that the Bible and tradition are sources of truth is associated with Catholicism. Catholic doctrine holds that the Bible is a source of divine revelation, but tradition and the teachings of the Church are also considered authoritative.