" Think of an engine and a compartment on a railway track. If a compartment is attached to an engine, it is duty of  a Sat Guru
to put a lock on the hooks joining the engine  to the compartment, so that the compartment can never get detached. The
engine is the Guru and the compartment, the soul of a devotee or desciple.Just like the hooks linking an engine to a coach become inseparable when the railway guard pushes in the rod through the joint,a Guru's duty is to lock the joining between a devotee and God. Then they can never get detached, even though there are ups and downs of life,like sorrows,calamities,and other disasters. If he fails to join the two, he fails in his duty"........Maharaj Sri Krishan Gopal ji Vyas.