A subject [noun] "provides" some thing or purpose [direct object, also a noun].
You "provide for" a target/purpose/circumstance [indirect object].
You "provide [a perhaps implied/unspecified noun] for" a [perhaps conditional, future, or abstract] target/purpose/circumstance.
When you "provide" something, the [noun] being provided is the subject of the sentence, and the result/outcome is the direct object. X provides Y. Ask: "What does the thing provide?"
A house provides shelter.
(S)A house (V)provides (D.O)shelter.
My job provides [me with] income.
This answer might (not?) provide clarity :)
"Providing for" something indicates the purpose or desired outcome, with the "what/how" for reaching that outcome perhaps implied or omitted.
The desired outcome or target receives the action, and is the object of the preposition "for," making it the indirect object. Ask: "For whom is the man's job providing?" For his family.
There could be a 2nd ("modal"?) verb in addition to "to provide/providing."
His job provides [income & other implied comforts] for his family.
His job allows him to provide [income & other implied comforts] for his family.
The contract provides [safeguards] for these circumstances.
The contract must provide [safeguards] for these circumstances.
A reason given in the U.S. Constitution for establishing the country is to "provide [a military] for the common defense."
Aside from all this, you also have "provided that..." as a conditional, where what follows describes what must happen in order for the stated outcome to occur.
You will get that raise, provided that you win us this contract.