Does giving charity out of compassion and happiness at bringing joy to the poor contradict sincerity?

A Muslim's feeling of happiness when he relieves a Muslim's distress or does him a favor does not contradict sincerity, unless it involves showing off or self-admiration. Rather, it is an evidence of the strength and completeness of faith, for the Prophet, peace and blessings be upon him, said: "He whose good deed delights him and whose evil deed grieves him is a believer."