The core beliefs of Marble Collegiate Church grow out of its history of Reformed Church theology, and in recent years incorporating the insights of modern psychology.

Marble Church proclaims faith in one God as expressed through the Holy Trinity; God the creator, the person of Jesus Christ, and the Holy Spirit. We believe the Bible, both the Hebrew and Christian scriptures, to be a unique and authoritative account of God's work in the world and interaction with humanity. The Bible is not to be interpreted literally, but is a guide for faith that yields insights and new life each day. We encourage members to read and interpret the Scriptures for themselves and to discuss their meaning together.

Marble Church recognizes two Sacraments: Baptism and Communion. Baptism is performed for infants, children, and unbaptized adult new members and symbolizes the person's welcome into the family of God. Holy Communion is the joyful feast of the people of God, remembering Christ's total and unconditional love for us and our fellowship and reconciliation with Him.

The contemporary psychological insights of Dr. Michael B. Brown, Dr. Arthur Caliandro, Dr. Norman Vincent Peale make the theological understanding of the mission of the church more relevant. Sin is an alienation from or a repression of our truest, God-given selves. Salvation is a search for wholeness, peace, and a living relationship with Christ. All persons are loved as sacred sons and daughters of God, and are openly included at Marble regardless of race, sexual orientation or background. Change and growth are primary at Marble -- growing in one's personal life, relationships, and in relation to God.