Rational proving of the Prophet and Imams' impeccable and immunity from sins

To be impeccable and immune from sins is necessary for the Prophet and Imams from intellect point of view. we mention some of them briefly:
Reason of accepting:
We should be able to trust Imams in intellect point of view. If we couldn't trust in saying, deed and writing of Innocent Ones (14 Innocent Ones: the Prophet Muhammad , his daughter, and 12 Imams) and if we suspect at their deeds , authenticity of all religious matters get in question. Then the Innocent Ones should be impeccable and without faults.
Reason of rejection:
If Imams and prophets say something but don't do the same, surely people don't accept that so nobody do divine laws.
Khaje Nasiridin Tusi said at Tajrid al Aghayed: " The Prophet should be innocent and impeccable so people trust them and to trust is the purpose of prophetic mission." [Kashf al Morad fi Tajrid al Eteghad, p.471]

According to the 59s verse of Surah Al-Nessa:

O you who have faith! Obey Allah and obey the Apostle and those vested with authority among you. And if you dispute concerning anything, refer it to Allah and the Apostle, if you have faith in Allah and the Last Day. That is better and more favorable in outcome. [Al-Nessa (Women), 4:59]

Absolute obedience of Imamas is mandatory and God has ordered us to do so just like he has ordered us to obey himself and his messenger.

Now regarding this theory the question is “If The Prophet and Imamas are not sinless and immaculate, would it be mandatory to follow them in every aspect?”

A positive answer will result in a contradiction. This is why from the above verse one can conclude that appointing Imamas as a must-to-follow-in-every-aspect means they are in fact sinless and immaculate.

Some prominent Sunni exegetes have also pointed this out

Ghertebi [?], a reliable and credible Sunni exegete, uses the following argument to prove the immaculateness of prophets.

All the expert followers of Malik, Abu-Hanifa and Shafei have said: “prophets are innocent from all small sins just like they are from major ones; because Allah has ordered us to follow them without question in every aspect, their actions, their work and their ways and has not mentioned any remark to contradict it. So if committing a small sin was possible for them, it would be impossible to follow them. Since, in that case, any action from them might be a good deed to get closer to God, a neutral action, a detestable or a forbidden one and Allah will never order us to do something that might be a sin.

So we conclude that absolute obedience from Prophet and Imams requires for them to be impeccable.

Source: https://plus.google.com/u/0/112354716705089420958/posts