How can a Muslim maintain his faith while oscillating between obedience and laziness, and what is the interpretation of Allah's anger with His creations despite His prior knowledge of their actions, and does divine anger imply a change in Allah's emotions?

The closest means to remaining steadfast in guidance are: seeking Allah's help, supplicating Him persistently, frequently remembering and thanking Him, renewing repentance, approaching the Quran with contemplation, striving against one's self, shunning the idle, and accompanying the righteous. As for Allah's anger, it cannot be compared to the anger of created beings, for "there is nothing like unto Him." His attributes befit Him, and we believe in them without asking 'how' or likening them to the attributes of created beings. We understand their effects, such as vengeance against disobedient ones.