Professor Hussein Ansarian pointed out in of his lectures that the Almighty God has appointed the Divine Prophets as leaders for you because they were flawless and infallible in thinking, ethics, and actions. God appointed them as leaders because he knew them and so that we have a flawless, perfect and pure role-models in our lives, and there is no obligation in obeying these leaders, and Almighty God has forced no one to obey him,the divine prophet and the Infallible Imams since the time of Hazrat Adam (as).
source : erfan.ir