Lets go through some parts of Master Sheikh Aliakbar Tehrani`s Lecture:
Imam Bagher was questioned: that our Creator Nurthrer says: not insist on what they did. Master said: they fall into error but not repent , fall into error but not regret, this is insisting on sin, some time, some day may God forbid you make 10 sins, 5 sins ,but regret afterwards, retract and God forgives you. You observe them sin but not mind.they think they must do it . they think they must backbite.They must disgrace someone.They must accuse,and not mind again.This means insist on sin.
Emam Reza was questioned, What is The limit of trust,Imam Reza said: That is don`t fear of any thing because of God`s presence, don`t be seared when God is Present.