Hold nothing back! This phrase implies an act of surrender, "no pretense"... giving your all. Many situations in life calls for us to surrender our will, wants or desires and at times even our needs. It is never our genuine interest to sacrifice what we want, to give up our will or desire. An action of this nature is very humbling. It makes one neglect their true interest in realization of (or to meet) someone else's need or want. We can look at "giving your all" in terms of doing your best (for you), or giving of your self to others. When I say "giving of yourself", I mean serving others (whole-heatedly) in meaningful ways.