How can a person avoid falling into hatred of what the Messenger, may God's prayers and peace be upon him, brought, while fearing polytheism by rejoicing in what God has afflicted him with, out of fear of not hating anything that would lead him out of the fold of Islam?

Rejoicing in success in obedience is commendable, for Allah the Almighty says: "Say, 'In the bounty of Allah and in His mercy - in that let them rejoice; it is better than what they accumulate.'" There is no harm in showing joy for obedience, as long as it is not for ostentation. Showing joy for a good deed is not a condition for it to be a righteous deed. Nor is it a condition to feel joy in affliction, for the Prophet, peace and blessings be upon him, grieved during calamities, but it is a condition to be content with Allah's decree and submit to it.