Jiang Mu didn't believe in fate, but the messengers who appeared around him were all "charlatans" who were proficient in fortune-telling. Moreover, it seems to be quite accurate! In addition to fortune-telling methods, each messenger also has his own unique skills, each one more talented than the other.
Originally, Jiang Mu was very resistant to becoming a spiritual envoy, but maybe it was fate, or maybe those "charlatans" were at work. In the end, he led these "charlatans" onto the path of spiritual envoys.