The very first advice sayyidi wa sanadi Hadhrat Mawlana Mohammad Taqi Usmani (may Allah preserve him) gave to a murid while giving him permission to instruct others,
“Never be negligent of your own self’s reformation (islah) effort.”
Hedayat bara-ay mujazeen
That is, the first and foremost in importance is my own self-reformation. Do not be missed led by Shaytan and nafs that I have graduated and now my primary concern is to do reformation of others.
This is a very common mistake.
Readers of the biographies of piously elders are well aware of the fact that how deligent they were in keeping their own self on tract. At the slightests indication of a slip they would jump and make amendments.
May Allah give us the tawfiq to do this also. Amin!
Manhattan, New York