All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
You should know that, by this revelation, Allah, The Exalted, intended to establish the irrefutable proof beyond the excuse of ignorance or reasonable doubt for people (so that mankind would have no argument against Allah). This cannot be done by means of incomprehensible, unclear, and ambiguous evidence but rather requires evidence that is clear-cut and unambiguous. Therefore, Allah, The Exalted, described His Book as Bayyin (clear) in terms of its wording and meanings.
He Says (what means): {And We have certainly sent down to you distinct verses,} [Quran 24:34] meaning ‘verses with clear-cut indications that clarify the pertinent religious rulings.’ He also Says (what means): {And We have certainly revealed to you verses [which are] clear proofs, and no one would deny them except the defiantly disobedient.} [Quran 2:99]
He also Says (what means): {And thus have We sent the Quran down as verses of clear evidence..} [Quran 22:16] meaning verses with clear wordings and meanings to establish irrefutable proof so that mankind will have no argument against Allah, The Exalted.
Allah, The Exalted, describes the Quran, in more than one occasion, as Mubeen (makes things clear). For example, He Says in the beginning of Soorat Yoosuf (what means): {Alif, Laam, Raa’. These are the verses of the Book that makes (things) manifest. Indeed, We have sent it down as an Arabic Quran...} [Quran 12:1-2] He also Says (what means): {…These are the verses of the Book and a Quran that makes clear.} [Quran 15:1] And in Soorat Yaseen, He Says (what means): {It is not but a message and a Quran that makes clear.} [Quran 36:69] As-Sa‘di said: "His Saying {…and a Quran that makes clear.} means that the Quran clarifies whatever needs clarification, and that is why the object is omitted from the sentence to indicate that it clarifies truth in its totality, by means of its detailed and general pieces of evidence, and clarifies falsehood and provides the proofs on its falseness, and this is the very nature of the divine revelation sent by Allah, The Exalted, to His Messenger.” [End of quote]
Some verses of the Quran may denote more than one meaning; these are called Mutashaabihaat (verses with unclear indications). Meanwhile, other verses with clear indications (Muhkamaat) adequately explain the Mutashaabihaat ones. Hence, some verses of the Quran explain others, and the Sunnah also clarifies the unclear indications of the Mutashaabihaat verses. The Sunnah as well explains and clarifies the meanings of the verses of the Quran. Thus, both the Quran and the Sunnah provide explanations for the verses whose specific intended meanings need to be identified. The Quran is not a book of mysteries, and the difference of opinion among scholars on certain issues (pertaining to the Quran) is not due to the fact that the divine revelation is unclear and incomprehensible. Rather, the scholarly difference of opinion occurs for many reasons, including the difference of people’s perceptions and understanding and the varying scopes of their knowledge.
As for your question about the wisdom for such difference of opinion, there are many pieces of wisdom. For example, this difference is a trial meant for distinguishing a believer who has sincere faith from the others. People vary in their pursuit of the truth, their keenness to reach it, and the efforts they exert to adhere to it. Another rationale is that the wisdom for revealing the Mutashaabihaat verses is to serve as a test for the slaves of Allah. Just as Allah tests people with good and evil, prosperity and adversity, and commands and prohibitions, He also tests them with the Muhkamaat and Mutashaabihaat verses. This meaning is clarified by the Saying of Allah, The Exalted, (what means): {It is He Who has sent down to you [O Muhammad] the Book; in it are verses [that are] precise – they are the foundation of the Book – and others unspecific. As for those in whose hearts is deviation [from truth], they will follow that of it which is unspecific, seeking discord and seeking an interpretation [suitable to them]…} [Quran 3:7] In his commentary on this verse, Ibn Katheer said: "In the Quran, there are verses that are Muhkamaat, with entirely clear indications that no one finds ambiguous, and other verses whose indication is not entirely clear for many people or some of them. Those who refer to the Muhkamaat verses to understand the Mutashaabihaat will be guided to the correct meaning, but those who go the other way around will not be guided." [End of quote]
Allah Knows best.