W-salaam,
I don't see how its the muhmin's responsibility to purify others but certainly his/her own to keep their own self in that state. The autonomy of choice is after all, what Allah(SWT) Himself reminds Prophet Muhammad(s.a.w) and the Qur'an listener/reader about. The muhmineen can explain and share their insights on how and why Allah(SWT) has ordained pure standards of personal conduct, though more often than not, are confronted by munafiqs and/or mushrikeen who seek to subvert and undermine the sanctity of the Qur'an vis-a-vis certain abusive 'hadith/sunnah' claims and who also attempt to corrupt them(muhmineen).
I don't see how its the muhmin's responsibility to purify others but certainly his/her own to keep their own self in that state. The autonomy of choice is after all, what Allah(SWT) Himself reminds Prophet Muhammad(s.a.w) and the Qur'an listener/reader about. The muhmineen can explain and share their insights on how and why Allah(SWT) has ordained pure standards of personal conduct, though more often than not, are confronted by munafiqs and/or mushrikeen who seek to subvert and undermine the sanctity of the Qur'an vis-a-vis certain abusive 'hadith/sunnah' claims and who also attempt to corrupt them(muhmineen).