I think the chain of logic in support of the idea is supposed to go like this:
Faith in necessary institutions is needed to keep them running. The institutions are deemed necessary because they keep #6734 and people like them safe. You owe #6734 et al. safety as part of the social contract. Therefore the institutions are owed your faith.
The assumptions beyond that I think are:
-The institutions actually keeps them safe (and not just feeling safe)
OR
-The institution only really keeps them feeling safe, but feeling safe is the actual value here worth preserving.
AND
-This social contract is in your best interests because it will be upheld for you too.
Faith in necessary institutions is needed to keep them running. The institutions are deemed necessary because they keep #6734 and people like them safe. You owe #6734 et al. safety as part of the social contract. Therefore the institutions are owed your faith.
The assumptions beyond that I think are:
-The institutions actually keeps them safe (and not just feeling safe)
OR
-The institution only really keeps them feeling safe, but feeling safe is the actual value here worth preserving.
AND
-This social contract is in your best interests because it will be upheld for you too.