CATHOLIC CATECHISM

THE COMMUNITY OF THE SAINTS

God hopes we all will become saints. The Church is a community that exists of three parts: the souls who are still living on the earth form the Church militant, the souls who are being purified in purgatory form the Church suffering (we will speak again of this later on), and the Church triumphant contains the souls who are already in heaven. Together, these three parts form the community of the (candidate) saints.
The saints can help us from their places in heaven by pleading for us with God, so asking for their intervention does make sense. For example, you may pray to your deceased grandfather or to somebody whom the Church canonized. We may also pray for the souls in purgatory and ask God to take them in heaven.
There are patron saints for numerous things. For instance, Saint Joseph, the fosterfather of Jesus, is the patron of the families. As a carpenter, he is also the patron of the workers. And, since he died in the arms of Jesus and virgin Mary, he also became the patron saint of a blissful death.
Everybody gets a personal patron saint when receiving baptism. Mine is emperor Hendrik II of the Holy Roman Empire, who lived about AD 1000.

In the first centuries after Christ there have been many holy martyrs. Some of them refused to adore the Roman emperor and were thrown before hungry lions. Saint Cecilia refused to abjure her faith and was beheaded. She is the patron saint of the church music. All these martyrs died out of love for God and man. (Nowadays, some people may call suicide terrorists martyrs, but they are wrong.)
In the middle ages there were many holy missionaries, confessors and founders of monasteries. Think of Saint Boniface, patron saint of Germany, or Saint Benedict, founder of the Benedictines.
In modern times, there are also countless saints. My mother had a little sister called Treesje. She was named after Theresia of Lisieux, the champion of the 'little way' to heaven, who was very popular in those years. Like her patron saint, our Treesje died of tuberculosis. Could this be another sign from God?