Why do I need a guru?
Teachers help us progress faster. They can see (if we let them) what we’re doing wrong, and help us correct it. Books can’t do that. Plus, you can close a book. A teacher may pursue you.
Krishna consciousness works best when three items are in place: guru (teacher), shastra (scripture), and sadhu (keeping company with other serious students).
The shastra is the knowledge upon which everything is based. It’s the starting point, the guide. It shows us the goal. How we apply that knowledge is another thing. Do we accept some things and not others? Do we consider part three of the scriptures to be of utmost importance while choosing to ignore part four?
The guru, the teacher, can see where the student is at, and help them adjust their course. A good teacher is always a good student also. They can preach because they practice. A sincere student can progress farther and faster with a teacher than without one.