So many of the things we hold onto keep us from experiencing a deeper spiritual life. Sometimes these things are material possessions (much like the rich young ruler) but more often they are things that flow from our ego.
What we fail to realize is that in letting we go we actually gain what we really want. Jesus says that "whoever wants to save their life will lose it, but whoever loses their life for his sake will gain it". Jesus gave his life completely and calls us to do the same. We are scared by what this looks like and we are unsure, so we hold onto our security and therefore never gain the depth in our soul.
Whatever helps us to let go is a gift, even if it means pain, struggle and suffering. These can be a gift if they are part of the paschal mystery where nothing is foreign to God.
Letting go is not fatalism, it is a deep and abiding trust. It is praying and living into "not my will , but thy will be done".