Hashem accepts the Torah of all Yidden, yet the more l'shmah and the more kedushah and taharah, the higher and the greater the Torah study.
The Chazon Ish said there are geniuses in our generation as there were in the past, yet we don't reach their levels. No one in our times is becoming a Reb Akiva Eiger zt'l, for example. This is because a great mind isn't enough. One needs kedushah and taharah, and in this aspect, we don’t compare to the scholars of the past (Maaseh Ish vol.2:10).
The Or HaChaim HaKadosh explains that a segulah is something that can't be explained with logic. This is unlike a refuah, a cure that can be explained logically and scientifically.
The Or HaChaim gives some examples. One is that when a goy studies Torah or keeps Shabbos, he is chayav misah (deserves to die), yet when a Yid studies Torah or keeps Shabbos, it's the greatest deed. This is something that can't be understood logically because if the deed is good, it should be good when a goy does it, too! It is a segulah, and we can't explain it with logic.
Another example is the desire to do a mitzvah or an aveirah. When a Yid intends to do a mitzvah, he is rewarded as though he performed the mitzvah, and when he wants to do an aveirah ch”v, he isn’t punished for his evil intentions. But for the goyim, the opposite is true. They are punished for their evil desires as though they committed the aveirah and aren't rewarded for their good wishes. Logically, we don't understand this rule, but it is a segulah, a rule that we accept without understanding.
Hashem promises the Jewish nation that if they receive the Torah (19:5), סגולה לי והייתם העמים מכל, "You shall be for the most beloved treasure of all peoples."
A segulah reminds us of the nekudah "segal," which is the formation of three dots (two on top and one beneath). The uniqueness of a segal is that even when it lies on its side, it remains a segal. Any way you turn it, it remains a segal. None of the other nekudos has this trait. Therefore, Hashem says, והייתם סגולה לי, you will be like a segal. This means, even if you fall, you will always remain the am segulah, a precious nation to Hashem.
