What is the advice for someone who fears disbelief and is unable to complete their studies?

A Muslim must fear disbelief and beware of it, and this fear should be healthy, driving him to strive in obedience to Allah and to be keen on faith, while relying on Allah and asking Him for protection from tribulations. However, this fear should not reach the point of a pathological fear that hinders worship and the pursuit of worldly interests. There must be a balance between fear and hope, having a good opinion of Allah, exerting effort in obeying Him, and focusing on studies and worldly affairs. Despair and despondency should not overcome a Muslim, for Allah loves noble matters and dislikes trivial ones, and He is pleased with diligence and excellence.