السَّلاَمُ عَلَيْكُمْ وَرَحْمَةُ اللهِ وَبَرَكَاتُهُ If I see a person and i know what he is doing is bidah or shirk, but I dont warn him, am I sinful. I am shy and i may not be able to speak properly.

Ustadh AbdulAziz al-Haqqan

If he accepts from you, you should advise him. This type of shyness is not praiseworthy; it is blameworthy. So you should, with wisdom and kindness of course, advise one another.