It's easy to blame others (and thus justify ourselves) for our disobedience. But in the following quote, Thomas Merton identifies the key reason why we fail to experience the freedom and joy Christ offers believers:

It is not that someone else is preventing you from living happily; you yourself do not know what you want. Rather than admit this [and ask for God's help], you pretend that someone else is keeping you from exercising your liberty. Who is this? It is you yourself.