This document discusses the doctrine of the Trinity through examining passages from the Heidelberg Catechism and Kevin DeYoung's book "The Good News We Almost Forgot." It explains that the Trinity refers to the one true God existing as three distinct persons - Father, Son, and Holy Spirit. Biblical evidence for each person of the Trinity is provided. While the Trinity is beyond human reason, it shows God's relational nature and how humans are made in His image to be relational beings.