Three main problems: narrow vision from within the Church, resistance to the message, and secular persecution. Despite what many Catholics are saying these days, the American problem is more the first than either of the others.
50. In the course of twenty centuries of history, the generations of Christians have periodically faced various obstacles to this universal mission. On the one hand, on the part of the evangelizers themselves, there has been the temptation for various reasons to narrow down the field of their missionary activity. On the other hand, there has been the often humanly insurmountable resistance of the people being addressed by the evangelizer. Furthermore, we must note with sadness that the evangelizing work of the Church is strongly opposed, if not prevented, by certain public powers. Even in our own day it happens that preachers of God’s Word are deprived of their rights, persecuted, threatened or eliminated solely for preaching Jesus Christ and His Gospel. But we are confident that despite these painful trials the activity of these apostles will never meet final failure in any part of the world.
A rather frank admission that barriers to evangelization are often thrown up by believers themselves. This is one of my worries with the “new” evangelization: an intentional narrowing of the scope, and a patting on the back for a job that was poorly done from the start. It’s also important to realize what actual Christian persecution is and what it is not. Being confronted with impolite ideological opponents is not persecution.
Despite such adversities, the Church constantly renews her deepest inspiration, that which comes to her directly from the Lord: To the whole world! To all creation! Right to the ends of the earth! She did this once more at the last Synod, as an appeal not to imprison the proclamation of the Gospel by limiting it to one sector of mankind or to one class of people or to a single type of civilization. Some examples are revealing.
And those examples are touched upon in sections 51-58, which we’ll examine more closely in the coming week of posts.
Catholic Sensibility 
The only thing left out is that we are all called to evangelize – CCC 2105.
And that most Catholics do not know their Faith well enough to accurately teach others or are not confident in their knowledge.
Either way Pope Benedict has taken care of that in PORTA FIDEI starting in paragraphs #11, in which he states that we should read and re-discover the CCC.
For documented links to Porta Fidei, the CCC, search engine on the CCC, info on the Plenary Indulgence regarding the “Second Vatican Council and the Catechism of the Catholic Church” (not other Councils or local catechisms), a brief video by Dr. Scott Hahn, and more, go to: http://whatcatholicsreallybelieve.com or search: ” What Catholics REALLY Believe SOURCE “.
If we all stick together and follow the instruction of our Pope, this could truly be a renewal.
The first evangelical witness requires little knowledge. Everyone is called to evangelize from their life’s witness. Knowledge about Jesus is good. Knowing Jesus is even better–and you don’t always get that from a book. Even the catechism.