We all wear masks.  We have to act in a way we don't feel like acting at times.  But don't forget that God can see right through our mask to our heart.  He knows what we are doing, what we are thinking and what are motives are.  The elder son in the Prodigal Son Parable wore a mask.  It is easy to think he is the "good guy" in the story until you look deeper and realize his motives for his behavior.  Don't be like the elder son and do the right things for the wrong reasons.