Our edicts are based on the teachings of the Imams of the Ahlulbait (peace be upon them) through the narrations that reached us in reliable ways, which all Muslims are required to act upon. The Prophet (peace be upon him and his holy progeny) ordered the nation of Islam to refer to the Ahlulbait and follow them in the famous well-known narration that is reported by numerous ways in the books of Shias and Sunnis: "I leave among you the two weighty things: the Book of Allah and my progeny; as long as you follow both of them, you will never be misguided."
Acting upon this narration, as well as other similar narrations, to follow the AhlulBait is not obligatory on the Shias only, but it is an obligation on all Muslims.

The said person is not considered as disobedient, but is liable for proceeding to commit an act that he was informed to be a sin. An example of this is if a person drinks from a glass thinking it to be wine, but it turns out to be water.

A believer should aim to fulfill the religious responsibilities of upholding the orders of the Sharia; one of them is learning the Islamic laws and teaching them. This could be achieved by learning more about the religion – and not necessarily reaching the level of ijtihad – by which a believer could serve Islam. One could serve the religion and be a role model amongst his society, family and friends by being obedient to the Islamic laws and by spreading the religious teachings in the areas where he resides. Therefore, ijtihad is not a goal that a student should have from the beginning.
Ijtihad is a talent that can be achieved by studying and with the guidance of Almighty Allah. A student of Islamic studies should study hard and make use of his time as much as possible. If he achieves this, then he can thank Almighty Allah for this bounty. If he does not, he can still serve the religion.

You should follow the scholar who has reached the level of ijtihad and fulfills all the other conditions of the marja in all issues.
The derivation of the edicts from the religious sources require a great amount of knowledge and experience gained from continuous studying and research over many years. The authenticity of the traditions is only one factor taken into consideration in this process. Only the scholars who have reached the level of ijtihad have the capability to undertake this.

It is natural to have different derivations, as people differ in their understanding of a single text, whereas the mujtahids deal with numerous texts, plus the fact that as time passes further away from the time of the texts, fallacies and probabilities increase. From this, the mission of a mujtahid becomes harder and his responsibility becomes greater in protecting the religion in a correct way and to the greatest possible extent. The oppressors and the liars throughout the times have made obstacles for us in obtaining the truths from the Imams (peace be upon them) which made the mission of the mujtahids more difficult. Therefore some variations are to be expected, in all areas of jurisprudence.

The difference in deriving the laws between religious jurists naturally originates from their difference in understanding the religious texts or considering some of them over the others. His Eminence, Sayyid Al-Hakeem (may Allah prolong his life) sees that alcohol is najis, if it is an intoxicant and naturally liquid. Based on this, the prayer is invalid if the praying person’s body or clothes came in contact with it.

If the layperson acted upon the edicts of the qualified marja he is following, then Almighty Allah will excuse him if his marja was not correct.

It is obligatory to inform the misinformed person if the latter is expected to act upon it.

It is not permissible to encourage them to disobey the edicts of the marja that they follow, in a way that the call to act in a certain way is with the awareness that it is against the edict of the marja that they emulate.
If someone asks about the ruling of a particular issue without stipulating that he wishes to the edict of his own marja or he does not have one to follow, then it is permissible to inform him of the ruling that is according to your own marja.

In this case, it is permissible for one to answer based on the edicts of his own Marja, and he does not need to give a reference of the source of the edicts or mention that there are other opinions of other scholars.

If the person who asks you does not intend to know the edict of a particular Marja. you may tell him the opinion of your Marja