The term “to stand against the Imam” should be made more clear. If it means not to act in accordance to the Imam’s desire the answer is yes. To sin, regardless of it being minor or major, leads to opposing God and the Imam. But if the mentioned term means that when one commits a sin he in reality opposes the Imam and rejects him and that the Imam would no longer accept the man as one of his followers, the answer is that it is dependable. Some of the sins are so great and make the man so corrupt and corruptive or the effect of those sins in one’s life and in his society is so profound and deep that it will be regarded as an act contrary to the mission of the Imam. However, there are some minor sins committed in secret that are done due to the lack of piety or sudden negligence or one’s inability against the power of lust and the like. These sort of sins do not necessarily mean that the sinner wants to oppose God and the Imam.