A MASUM (sinless person) has power to commit sins...

A MASUM (sinless person) has power to commit sins; but he does not even think about sins because his spiritual standard is so high that such inferior things do not enter his mind. The Sunni scholars do not speak with one voice in this subject: They first differ about the point when sinlessness of prophets begins. Some Sunnis say it is after the declaration of prophet-hood; others say that it is since childhood.

The scope of sinlessness before declaration of prophet-hood: Some Sunni scholars say that it covers all sins; the majority say that they are protected from KUFR (infidelity) only. The scope of sinlessness after declaration of prophet-hood: It is agreed that the prophets do not tell lie after prophet-hood. But what about other sins?

Some Sunni scholars say that they commit other sins either intentionally or unintentionally; but the majority say that they could commit it unintentionally, but not intentionally. The minor sins: Some Sunni scholars say it was possible for prophets to commit minor sins, even intentionally. But that they were protected from such minor sins which might have degraded them in the eyes of people.

The Shia point of view about sinlessness is that all the prophets were sinless and infallible; they did not commit any sin, whether capital or minor, and whether intentionally or unintentionally; and that they were sinless from the beginning of their life till their last breath. About the prophets, Shaykh Saduq wrote: "Their word is the word of God, their order is the order of God, their forbidding is the forbidding by God ...

And that the Chiefs of the prophets are five, and they are (called) 'Ulul-Azm' and they are Noah, Abraham, Moses, Jesus and Muhammad (be blessings of Allah upon them all) and that Muhammad is their Chief and best of all." IMAM (LEADER): Shiats say that Imam must be appointed by God; that appointment may be known through the declaration of the Prophet or the preceding Imam.

The Sunni scholars say that Imam (or Caliph, as they prefer to say) can be either elected, or nominated by the preceding Caliph, or selected by a committee, or may gain the power through a military coup (as was in the case of Muawiyah). Shia scholars say that Imam must be sinless. The Sunni scholars (including Mutazilites) say that sinlessness is not a condition for leadership.