Hi C-duo,
This is a convoluted sentence indeed. We can study a subject but we cannot "study" knowledge. However, we can "acquire" or "gain" knowledge. "Acquire" means to gather something through a constant effort.
Moreover, "again" has the meaning of a repetitive action. Therefore, the repeated use of "again" is redundant.
Perhaps the slogan could be:
1) Knowledge is gained / acquired through consistent thought.
2) The gain / acquisition of knowledge is derived from consistent study and thought.
3) Consistent study and thought brings about knowledge.
Hope this helps.
Cheers,
Lance