The most common and most likely answer to this crossword clue is the 6 letter word THEISM
I've seen this crossword clue in The Times
T
H
E
I
S
M
More clues leading to the result THEISM
- Faith is embraced by enemy of US
- Belief is within people against us?
- Belief is held by other people
- It may give me this belief in God
- Protected by Christ; He is my religion
- Belief is held by those folk
- Belief as source of hope in troubled times?
- Belief is maintained by individuals opposing us
- … belief. It’s finished taking His Eminence’s Mass
- One has Mass supporting article of faith
Buddy explains!

The straight part
We know that "Faith" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case faith = theism.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does THEISM mean?
THEISM noun- Belief in the existence of at least one deity.
- (narrowly) Belief in the existence of a personal creator god, goddess, gods and/or goddesses present and active in the governance and organization of the world and the universe. The God may be known by or through revelation.
- A morbid condition resulting from excessive consumption of tea.