“K’se’irim aley desheh v’k’revivim alei eisev” – “Se’irim” is a storm; "revivim" is the morning dew. Rashi says “desheh” refers to vegetation as a whole; “eisev” is the individual blade of grass. It’s not the same Torah, the same “likchi,” for everyone. For some people, Torah is like a hurricane. Other people can’t take that. They need Torah to fall gently, like the morning dew. There is the Torah that applies to the “desheh,” the community, and there is the Torah of each “eisev,” each blade of grass with its own needs.
How is the Torah like dew? R’ Simcha Bunim m’Peshischa explained that when the dew falls, it has no noticeable effect on the plant. It’s only later, after time, that its effect is felt. You can't open a sefer and expect a magic transformation to occur. It takes time, but the growth will happen.
Final point -- a question: Ramban writes that Parshas Ha'azinu speaks of ultimate redemption with no conditions, no prequalifications -- it's going to happen, take it to the bank. Yet the gemara (Sanhedrin 96) quotes R' Eliezer's view that geulah will happen only if Klal Yisrael does teshuvah. R' Yehoshua disagrees only to the extent that he holds teshuvah itself is inevitable. If Klal Yisrael doesn't do teshuvah of our own accord, then Hashem will cause us to be subjected to the decrees of an evil king