Here are some reading highlights from Lloyd-Jones on this verse...
“'He must increase, but I must decrease.' Are you proud of your religion? Are you proud of the good life you are living? Believe me, once you know something about this you will hate all that; it will have to go, decrease, disappear."
"The greatest enemy in the Christian life is self. By that I mean the greatest enemy within us."
"The Law has been given very definitely in order to show us exactly what we are. 'The law . . . was added,' says Paul to the Galatians, 'because of transgressions' (Gal. 3:19). It came to pinpoint sin, to convict us, to show us the truth about ourselves."
"There is nothing more humbling than the law, for it shows us exactly where we are."
"Self-centeredness is the bane of the Christian life, the curse, the main relic of sin and of the fall in every one of us, even as Christians. Your battle with self is really just beginning when you are converted."
"God forbid that we should reduce this glorious gospel of the blessed God to something that is merely an agency to provide particular blessings for us."
"It is the failure to realize that we are “dead” [having died with Christ] that accounts for this persisting self and this self-sensitiveness, self-protectiveness, and self-defensiveness."
-- Martyn Lloyd-Jones, Experiencing the New Birth (Crossway, 2015)