Rav Avigdor Miller on Belittling Yourself
Q:
How can someone know if he’s really gaining excellence as the result of his service of Hashem and his good deeds, or maybe he’s deluding himself – maybe just deceiving himself into believing that he is becoming better?

A:
There’s only one way to work that out – and that’s to always belittle yourself, to consider yourself a nobody. And so you’ll remember that even when Moshe Rabeinu was already on that high level of reflecting all the great things of the perfection of his soul; the level of תמונת השם יביט – seeing the form of Hashem, still Moshe Rabbeinu said ונחנו מה – Who are we? What am I? The gemara says Moshe considered himself even less than Avraham Avinu. Avraham said at least that he’s dust and ashes. ואנכי עפר ואפר – I am dust and ashes (Bereishis 18:27). But Moshe Rabbeinu said ונחנו מה – We’re nothing at all.

So Moshe Rabbeinu was always on the safe side – no matter how great he was, he said he’s nothing. So if your neshama is reflecting right now some ruach hakodosh, then don’t advertise it. Because that’s a pretty good sign that it’s not the real thing. Anybody who claims he can accomplish miracles, it’s a pretty good sign he’s far away from miracles. The man who works miracles is a man who doesn’t know that he can work miracles.