Jesus enjoins his disciples to prefer him to everything and everyone, and bids them "renounce all that [they have]" for his sake and that of the Gospel. Shortly before his passion he gave them the example of the poor widow of Jerusalem who, out of her poverty, gave all that she had to live on. The precept of detachment from riches is obligatory for entrance into the Kingdom of heaven.
Source: Catechism of the Catholic Church (Vatican.va)