It depends. Many people testify how angels protected them etc.
I don't doubt, but that doesn't make it so. In every case where these things have been put under scrutiny, it's always turned out to be a natural cause.
Often, it's a case of the survivor's fallacy: they get into a serious accident, like a car pile up, and they survive. Since this is an unlikely outcome, they assume that it
can't be chance, that there
must be an active cause that made them survive - and they conclude God, or angels, or spirits, or ghosts, or whatever, is what saved them.
The truth is that they really were just lucky. If there's an accident where there's a mere 1 in 1000 chance of survival, then you're
still going to get some people survive by sheer chance, But those actual individuals are hard-pressed to accept this statistic, because the human brain isn't wired that way - it demands a cause. So, it invents one: angels (or gods, etc).
So I don't doubt for a second that people
believe they were saved, but it's never been shown that these 'miracles' are anything more than merely unlikely events. So, testimony means nothing, as it's either a) unverifiable, b) exaggerated/made up, or c) studied and debunked. People get things wrong, and there are real phenomena that make people
think it's something supernatural when, in fact, it's not.
So - how do you differentiate between something unlikely that happens that people
think is due to angels, and an actual intervention by an angel?