Thanks for asking a question on thisisyourbible.com.
James 3:1 My brethren, let not many of you become teachers, knowing that we shall receive a stricter judgment.
Let not many of you become teachers: In some measure these words applied to the household of faith but more pointedly did they apply to the rich: the Pharisee, the Sadducees and the Scribes. See Romans 2:17-21! They were so proud of their understanding of the law and yet they understood not one jot of it. How pathetically sad that the belief they held so tenaciously would be but a one-way ticket to destruction at the judgment seat of their long-awaited Messiah. May the same not be true of us!
Judged more strictly: Note Romans 2:3 "judgement" here is the same Greek word, Krima, as in James "stricter judgement". Knowledge brings responsibility. The greater one’s knowledge the more good or ill one may do. With the responsibility of teaching comes the duty to live an exemplary life. A teacher is looked-up to and his example emulated by those who hear him. Those who take the mantle of teacher take on a heavy burden of responsibility. With that responsibility comes a greater measure of accountability.
I hope you have found this helpful.