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.
