Under what circumstances doing a usually bad work with good intention permissible?

I recently heard this from a cleric : > Suppose if two friends had some disagreements or fight with each other. Now, to re-establish their friendship bond and unite them, you can separately lie to each of them. For example, if the two persons are A and B, then you can lie and say to A that B praises you very much and vice versa. By this, two friends will re-unite again and lying in this situation is not only just permissible but also a very good act. But I have also heard that it is not allowed to do bad deeds like stealing money with good intentions like giving the stolen money to charity. So, I want to know that under what conditions will doing a usually bad deed with good intention be permissible ? ( Assuming that what cleric said was not incompatible with Islam)