Allah's most important names are about giving mercy (ah-raheem, ar-rahmaan), and Allah states that he has the power to guide and save all of humanity (Surah 10:99, 6:149, 2:). Yet, he says that there will be those who disbelieve and are going to eternal punishment (Surah 4:56). So, either Allah's mercy and justice are selective (challenging His described attributes), or His omnipotence is limited (undermining His divine nature).