The Source of all Power is the Spirit. It lends its energies to the mind, heart and bodily life. Now it is up to us (to an extent) to use this energy or power which is given to us by the Divine. When we use it rightly according to our genuine human needs turning the rest, towards progress (in different ways and along the lines of our nature) then these powers increase in us. If we turn them towards the Divine then they not only increase in quantity but begin to undergo a change in quality. This is the logic of spiritual evolution.
A reasonable moderate expenditure of energy for genuine human ends which includes sexual interchange for progeny and for a certain intimacy and physical union when two beings are truly in love keeps the normal balance of our human state. On the other hand indulgence and waste of energy for pleasure, relieving boredom in activities such as excessive sexual indulgence, gossiping, animated vital interchanges, partying and all the rest naturally drains the energy given to us for health, harmony and progress. What is worse is that we draw the deficit from very inferior sources through various forms of interchanges.
Some get completely caught in a vicious cycle or a web of dark forces that pulls them towards an Asuric and even demonic life. Even if one is saved from such extremes, an excess of any kind on the physical, vital and mental domain makes one prone to illnesses and loss of vitality with ensuing frequent fatigue that makes one vulnerable to various forms of psychological disorders such as Depression as well.
This is where the necessity of sexual control as well as other forms of control such as of speech, emotions and vital activities stands. It is not so much a moral as it is a scientific principle which is quite consistent with logic as well as common sense.
About Savitri | B1C2-13 The Godhead Behind Nature’s Machinery (pp.20-21)