Image source: Myself
All the spiritual literature like Ramcharitmanas, Bhagavad-Gita stresses on the importance of spiritual master and creates a desire in persons on the path of self-realization to get themselves initiated by Spiritual master.
The spiritual master is the one who removes the bad qualities or evils from his disciple's heart and converts them into good qualities like renunciation, selfless work, devotion to God, peace, tranquillity, mercy, charity, equanimity. This is just like the sun which converts salty water of the ocean into sweet rainwater by process of evaporation and sublimation.
Even then people with poor funds of knowledge do not understand how the spiritual master is making their life blessed. While in service to the spiritual master, we have to keep our cleverness and intelligence separate and follow directions of our spiritual master with our heart and soul. We have to serve spiritual master with body, mind, money.