Baltimore Catechism No. 2 – Lesson Third on the Unity and Trinity of God

Q21: Is there but one God?

A21: Yes; there is but one God.

Q22: Why can there be but one God?

A22: There can be but one God, because God, being supreme and infinite, cannot have an equal.

Q23: How many Persons are there in God?

A23: In God there are three Divine Persons, really distinct, and equal in all things—the Father, the Son, and the Holy Ghost.

Q24: Is the Father God?

A24: The Father is God and the first Person of the Blessed Trinity.

Q25: Is the Son God?

A25: The Son is God and the second Person of the Blessed Trinity.

Q26: Is the Holy Ghost God?

A26: The Holy Ghost is God and the third Person of the Blessed Trinity.

Q27: What do you mean by the Blessed Trinity?

A27: By the Blessed Trinity I mean one God in three Divine Persons.

Q28: Are the three Divine Persons equal in all things?

A28: The three Divine Persons are equal in all things.

Q29: Are the three Divine Persons one and the same God?

A29: The three Divine Persons are one and the same God, having one and the same Divine nature and substance.

Q30: Can we fully understand how the three Divine Persons are one and the same God?

A30: We cannot fully understand how the three Divine Persons are one and the same God, because this is a mystery.

Q31: What is a mystery?

A31: A mystery is a truth which we cannot fully understand.