"If we had possessions we should need arms for their defense. They are the source of quarrels and lawsuits, and are usually a great obstacle to the love of God." - Francis of Assisi There is a strong connection between property and peacemaking. Most every action of violence or aggression is prompted by some form of property for which there is either a debate for who deserves possession OR someone has attempted to steal possession from the rightful owner.
For this reason, we have to always protect the things that belong to us. The more possessions we have or the more a particular possession costs, the more aggressive our defense of that item has to be. Instead of a focused attention on defending the poor and widowed that God calls us to defend, we have wasted our soul's energy defending the property and possessions we have acquired.
The more things we have, the less peaceful our hearts can be. With more possessions comes more defense, more protection. With more things comes more quarrels.