‘Ya’subal-din’ and ‘ya’sub al-momenin’are two medals of honorgiven by the Prophet (p.b.u.h.)to Ali (a.s.). The essential challenge of these titles concernsverification of their meaningand credibility. The main question related toverification of their meaning is,‘What are the characteristics of a faithful person that he has been likened to bees and their commander is called ‘ya’sub’?.Also, with regard to verification of their credibility, some Sunni scholars have denied this virtue of Ali (a.s.) and considered it some kind of fabrication. In this paper, to prove that these titleshave been given to Ali (a.s.) by the Prophet (p.b.u.h.), the related narrations are logically categorized and presented. It seems that we can understand these titles better by taking into account such semantic elements as taqiyyehand keeping secrets, exterior and interior purity, obeying the command of a leader, not harming others, being beneficial to others and being blessed by God.