All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
The perfect way to deal with such people is by setting a good example for them through good conduct, speech and deeds. Moreover, one should advise them wisely and gently, and should show them that she/he is keen on guiding them to the right path and should supplicate Allaah The Almighty to guide them.
Allaah Knows best.