A person is capable of distinguishing good actions from bad ones because he possesses reason and a conscience, which enable him to make clear judgements. [1749-1757, 1757-1758] The following guidelines make it easier to distinguish good actions from bad ones: (1) What I do must be good; a good intention alone is not enough. Bank robbery is always bad, even if I commit that crime with the good intention of giving the money to poor people. (2) Even when what I do is truly good, if I perform the good action with a bad intention, it makes the whole action bad. If I walk an elderly woman home and help her around the house, that is good. But if I do it while planning a later break-in, that makes the whole action something bad. (3) The circumstances in which someone acts can diminish his responsibility, but they cannot change at all the good or bad character of an action. Hitting one's mother is always bad, even if the mother has previously shown little love to the child.
We are here on earth in order to know and to love God, to do good according to his will, and to go someday to heaven. [1-3, 358] To be a human being means to come from God and to go to God. Our origin goes back farther than our parents. We come from God, in whom all the happiness of heaven and earth is at home, and we are expected in his everlasting, infinitie blessedness. Meanwhile we live on this earth. Sometimes we feel that our Creator is near; often we feel nothing at all. So that we might find the way home, God sent us his Son, who freed us from sin, delivers us from all evil, and leads us unerringly into true life. He is "the way and the truth and the life" (Jn 14:6).
The Greek word for CHURCH is “ekklesia”= those who are called forth. All of us who are baptized and believe in God are called forth by the Lord. Together we are the Church. Christ is, as Paul says, the Head of the Church. We are his body. When we receive the sacraments and hear God’s word. Christ is in us and we are in him that is the Church. The intimate communion of life with Jesus that is shared personally by all baptized is described in Sacred Scripture by a wealth of images: here it speaks about the People of God and in another passage about the Bride of Christ; now the church is called Mother, and again she is God’s family, or she is compared with a wedding feast. Never is the Church a mere institution, never just the “official Church” that we could do without. We will be upset by the mistakes and defects in the CHURCH, but we can never distance ourselves from her, because God has made an irrevocable decision to love her and does not forsake her despite all the sins of her members. The Church is God’s presence among us men. That is why we must love her. (You cat – 121)
Using drugs is a sin because it is an act of self-destruction and thus an offence against the life that God has given us out of love. Every form of a person’s dependence on legal substances (alcohol, medication, tobacco) and even more so on illegal drugs is an exchange of freedom for slavery; it damages the health and the life of the person concerned and also does great harm to the people around him. Every time a person loses or forgets himself by becoming intoxicated which can also include excessive eating and drinking, indulgence in sexual activity or speeding with an automobile, he loses some of his human dignity and freedom and therefore sins against God. This should be distinguished from the reasonable, conscious and moderate use of enjoyable things. (You cat-389)