Is it permissible to seek knowledge from a shaykh who commends and follows preachers whom scholars have warned against, while the student fears temptation?

The danger of slandering the honor of preachers and righteous people is immense. Not every disparagement of a commendable person necessitates shunning him. If a person is steadfast upon the Sunnah, benefit from him and do not pay attention to claims of doubt. Beware of backbiting and be keen on having a pure heart towards Muslims, especially preachers. The commendation of some preachers does not imply an innovation that warrants caution against them. Rather, emulate them in seeking goodness from everyone. As for one who errs, his error should be avoided, and his correct teachings should be benefited from.