After Trump's false prophet act, I understand why Biden feels the need to invoke faith. It's unfortunately expected.
Plus, Biden, as head of the Democratic Party, likely has pressure to prove that Dems are as religious as the RWNJ's.
Plus, Biden is genuinely pious. He may have been inspired at the moment.

And then his son's death.

It was a coping strategy which saved him.

Deeply ingrained, he falls back on it during times of crisis.

It is not a bad thing, it gives him a confidence, strength and optimism.

of faith.

Faith is up to the individual involved. I really don’t think that Biden’s statement is a huge issue.

"firm belief in something for which there is no proof. " Merriam Webster
What ever works for you to get thru the day and not harm or hurt anyone. YMMV
m

Has been co-opted by the uber religious and/or foisted upon those who are just trying to avoid the word religion.

Faith, in my interpretation and it bothers me that so many think it is a synonym of religion:

The strong sense that some thing or event is what one expects it/that to be whether there is tangible evidence or not.

Their euphemisms are not just inaccurate. They sound stupid

They should use the term belief system as it is called by anthropologists.

the whole "spirituality" thing. Means all things to all people and is thus completely empty of meaning.

in "faith" in the supernatural which is unprovable, and "faith" meaning confidence, based on accumulated evidence. Faith in god is of the first type. Faith that the sun will come up, that I can't survive this dive off this cliff, or that my dog loves me, is of the second.

and was speaking to a largely Catholic Polish crowd.

He might have issued a sop to god, but he's also sending weapons to Ukraine and humanitarian aid to countries refugees are fleeing to.

That puts him way ahead of the thoughts and prayers Republicans. I don't care what he believes or says. I care about what he does.