The Holy Trinity
God is love. What does that mean? We can say that we love ourselves, and it's good to have an appreciation for who we are, but this is not the kind of love we speak of. We when speak of love we mean to freely give ourselves to another person. We can say God is love because he is a Trinity- three Persons in one God,
God is great- so great that many mystics and Doctors of the Church say that God is "unknowable". Every time we may think we know God he removes a set blinders and we see what we have discovered is In fact merely the tip of some immense iceberg. There is an infinite, inexhaustible richness to God's greatness and his love. We can never come close to fully understanding who God is. But this fundamental richness of who is God does not take away the fact that there are things we can know with certainty about him, and in fact must proclaim with conviction.
God is a community of love. He is three persons in one God, and the three persons are equal. Each is fully distinct, each is fully God. The Father is not more eternal than the Son, nor is the Son more glorious than the Spirit, nor is the Spirit more loving than the Father. Each is equally powerful, each is equally glorious, each is equally loving. We tell them apart by how they relate to each other and to us.
God is also the archetype of all good relationship, the foundation of every act of love. That means that every single good deed is some reflection of who God is. His image is everywhere, in every single act of love. Every act of love consists of a person who initiates love, a person who responds, and the spirit that this exchange happens in. Dance is not the only image of the Trinity we can or should use, but it's one of the best images because it makes the relationship so clear. The leader is the symbol of the Father, the follower the symbol of the Son, and the music is the symbol of the Spirit.
The Father is called Father because he eternally begets the Son. This does not mean that the Father existed before the Son. Rather we say that the Father is the one who initiates relationship, like the leader in the dance. Everything finds its first origin in the Father. He has a plan that he communicates to his Son, like pattern. This plan is not merely information but the gift of the Father himself, and this plan is not for his benefit but rather for the glory and exaltation of the Son, his follower.
The Son is called Son because he is eternally begotten of the Father. The Son's joy is to do the will of the Father. In doing so we say that he is the Word of God, that he expresses the plan of the Father in his person, like in dance the pattern that the leader communicates is seen in the body of the Follower. The Father does not do anything alone, but does everything through is Son, that "through him, all things were made, and without him nothing came to be" (John 1:3)
In the dance the leader and follower share one music, which unites the couple and informs the dance. In the Trinity the Spirit is the love that proceeds from the Father and the Son. The Spirit is like a musician who plays for the couple. He is a person of the same nature as the Father and the Son, and shares his music as a gift to them. The Spirit is also like music, which is shared equally and fully by both the leader and the follower.