As Muslims we believe in the Prophets (all of them). They are completely and totally truthful in that which they informed their people about, which came from Allah. Truly believing in this without a doubt, when mixed with information about those thing that they informed us about, will surely cause some change in us and our lives. As we said before, true belief necessitates action.
Also, we believe that Allah has given all of them miracles and signs showing the truthfulness of their messages. This again helps us to build the belief we have been commanded to have in them and that with which they came. We believe that they have completely and correctly delivered the whole of their messages without leaving out even one letter. Not only that, but we believe that along with delivering the message, they explained to the people that which Allah wants from them.
Due to all of this, and other things, it is necessary for us to respect all of them. We do not accept some, and deny others. We do not curse any of them. We have been commanded to respect them, speak good about them and love each and every one of them. Do you see yet, how our having knowledge of these things, and true belief in them would cause or necessitate action, and not just making empty claims?