Reading through the book of James again, I am in full agreement that not many should become teachers. Regarding the “stricter judgement”, will that judgement come from man or God? If from God, how and when will He administer stricter judgement as compared to the rest of the saints?
You’re referring to James 3:1, which says,
Not many of you should presume to be teachers, my brothers, because you know that we who teach will be judged more strictly.
God is our only judge so the judgment will come from Him, and it will take place at the bema judgment after the rapture. Believers cannot lose their salvation, so the judgment will come in the form of loss of rewards. In 1 Cor. 3:10-15 Paul said our works that are judged to be as gold, silver, or precious gems (having value in the Kingdom)) will survive but those judged as wood hay or straw (having no value) will be burned up.
As to being judged more strictly, from James 3:2 it seems clear that perfection is not the standard, but in James 3:14-16 there’s a hint that envy and selfish ambition are two criteria for judgment. In my opinion these are two motives that are becoming more obvious, especially among the well known teachers of our day.