What is the ruling on one who is ignorant of one of Allah's Beautiful Names, such as Allah's name "Al-Hakam" (the Judge)?

Ignorance of some of Allah’s names and attributes is an excusable ignorance for a servant, and he is not to be judged as an infidel until proof is established against him. Among the evidence for this is what Al-Bukhari narrated from Abu Hurairah, may Allah be pleased with him, from the Prophet, peace and blessings be upon him, who said: "There was a man who used to commit excesses against himself. When death approached him, he said to his sons, 'When I die, burn me, then grind me, then scatter my ashes in the wind. By Allah, if Allah has power over me, He will punish me with a punishment He has not inflicted upon anyone.' When he died, they did that to him. So Allah commanded the earth, saying, 'Gather what is in you of him,' and it did so, and behold, he was standing. He said, 'What compelled you to do what you did?' He said, 'My Lord, Your awe (or Your fear).' So He forgave him." This hadith (definition) indicates that this man did not know Allah Almighty's power to gather him after he ordered them to burn him and scatter him in the wind, yet Allah forgave him.