1. God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life(John 3:16).
2. The image we have for God is very influential in our relationship with Him and with others. Many see God as a stern judge waiting to strike us down for the least mistake. Others view God as kind of absent minded inventor who has made us, and then went off to do something else. There are those who believe in many gods, in order to account for various characteristics each one possesses. A large group of people worship wealth or money, and will do anything necessary to serve their god. And of course there are a large number of people who worship themselves, especially their appetites. Whatever is pleasing to themselves they want, and other people or even the common good of society is of no interest to them if it were to interfere with getting their way.
3. But as Catholics, who do we say that God is? When we came into the Church, we blessed ourselves and said in the name of the Father, and of the Son, and of the Holy Spirit. Not, the names, but the name. The same is true with how we began Mass: in the name of the Father, and of the Son, and of the Holy Spirit. We believe in One God, there are simply not many- that defies reason. If there were many, which would be in charge? Would not the one in charge really be god and all the rest some other kind of thing? Anyway, we believe in one God, in three persons. Not three gods, not three masks that the one god wears, not three modes of being, not three hats- three persons in One God- Father, Son, and Holy Spirit.
4. The truth of the Holy Trinity is not something which the Early through their wisdom and goodness figured out on their own. No, that God is a Trinity of Persons in a Unity of Divinity is a truth which God has revealed to us. In God, the Persons of the Trinity love one another perfectly and are in perfect union- God is a communion of Love.
5. The nature of One God in Three Persons is not simply a fact of who God is, but this fact touches (or should touch us) us in profound ways. In place of a judge, a Father, in place of a Punisher, an obedient Son who offers Himself in Sacrifice for the guilty. In place of an absentee creator, the Holy Spirit dwells within us to guide us on the path to holiness of life.
6. The world needs the Holy Trinity. Not simply from the point of view that the Trinity is God, and the world needs God. That is true enough, but each of us need the Trinity more than we think. God invites us into the intimate relationship between the Father, Son, and Spirit. As human beings we are social and communal creatures. We need community. Without community, a person will be stunted and incomplete, even from just the human point of view.
7. Consider the example of a child. Without a good healthy relationship with both mother and father, a child will not mature in a healthy manner. If there is physical, sexual, emotional or spiritual abuse, then the damage could be severe. It is very common that those who are victims in one generation become those who abuse in the next. The most common form of abuse is neglect- that is a person not having their needs fulfilled, whether they are physical, emotional, social, or even spiritual needs. Blessed Mother Theresa said that the most terrible and common form of poverty was loneliness.
8. If terrible things happen to a person and to society because a person does not have their need for community met, what would happen to us if our need for communion with God was not fulfilled. Without communion with God, a human being will be stunted and incomplete spiritually- they will not be what they are made to be.
9. God said through Scripture that even if a mother would forget her child, that He would not forget us. The love of the Holy Trinity is a relationship which God is calling us to experience and to share. This love is not affected by human weakness or sin. We cannot earn it and we cannot lose it, because it is a gift from God. We can refuse it or accept it, like any gift. We enter into this relationship most notably through the Sacraments of the Church, but for those who are aware, the love of the Trinity surrounds us at every moment of every day.