How can one distinguish between thinking well of Allah and Satan making a deed seem fair, along with the assumption that what awaits is good?

The good expectation of the one who performs acts of obedience and avoids sins towards Allah Almighty is encouraged, as the Prophet, peace and blessings be upon him, said: "I am as My servant thinks of Me. If he thinks good of Me, he will have it; and if he thinks evil of Me, he will have it." As for the expectation of the one who is negligent in acts of obedience and falls into sins, it is a delusion from Satan, because expectation follows action. It is not permissible for a wrongdoer to have a good expectation in order to be saved. A person must obey Allah's command and avoid His prohibitions, and then have a good expectation of his Lord that He will reward him and forgive him. When meeting his Lord, a Muslim should have the best expectation of Allah's forgiveness and easy acceptance due to His generosity and bounty.