The awliya’ of Allah are people of faith and piety who are constantly aware that Allah is watching them in all their affairs, so they adhere to His commands and heed His prohibitions. The degree of wilayah varies according to a person’s faith and fear of Allah. Wilayah is a divinely granted status that begins in the heart with love and veneration of Allah and is reflected in a person’s behavior. Wilayah does not mean that a person can do haram deeds or omit obligatory duties. The best of the ‘awliya’’ of Allah are the messengers and prophets, then the Companions of Prophet Muhammad (peace and blessings be upon him), then those who came after them, then those who came after them. We do not know that the phrase “ashab Allah (friends of Allah)” was given to any of them.

No one knows the absolute unseen except Allah. A person may learn of that which is relatively unseen either through revelation, or through life experience, or through empirical science, or other means.

What is commonly said by some people, that it is possible for a person to wrong his Lord and to wrong himself and to wrong others is not correct. Rather the correct thing is to say that the person did wrong with regard to his relationship with his Lord.

There is no difference between you saying “In sha Allah” or “Bi idhnillah.” That is for several reasons which are detailed below.

You are right to tell them off, because they are coming close to kufr with these words. Changing one letter does not alleviate the grievousness of their error.