This weekend's gospel was the parable of the two sons. It's kind of the short version of the prodigal son. A man with two sons goes to his first son and asks him to help in the vineyard. The son says no but eventually goes. The other son says yes but never quite gets there.
Jesus is using this parable to point out that some who seemed to be on the fast track to hell ended up changing their ways and going to heaven. Whereas some people who seemed so holy were sinning but not repenting, let alone even coming to recognize their sin for what it was.
All have sinned and fallen short of the glory of God. None of us are perfect. That's why we have the sacrament of Reconciliation. It keeps us humble and helps us get the job done.