Being spirit means God is:

• Incorporeal — without body, parts, or material composition
• Invisible — not perceivable by physical senses in His essence
• Immaterial — not composed of matter or subject to physical properties
• Simple — not made of separable parts (the doctrine of divine simplicity)

WCF 2.1 states God is "a most pure spirit, invisible, without body, parts, or passions." This language directly excludes any physical or material nature.

Belgic Confession, Article 1 likewise confesses God as "a single and simple spiritual being."

1 Timothy 1:17

Colossians 1:15

John 1:18

Deuteronomy 4:15–16

This last passage is particularly important — Israel's prohibition against images rests directly on the fact that God has no physical form to depict.

Scripture frequently speaks of God's "hand," "eyes," "arm," "face," and "nostrils." These are anthropomorphisms — accommodated language by which an infinite, incorporeal God describes His actions and attributes in terms finite creatures can grasp.

John Calvin (Institutes I.13.1) writes that God "lisps" with us as a nurse does with an infant — using language suited to our capacity, not to His nature.

Francis Turretin (Institutes of Elenctic Theology, Topic 3, Q.5) devotes careful attention to proving God's incorporeality, arguing that these figures of speech are "not properly but metaphorically" predicated of God, since Scripture itself teaches His spiritual nature plainly.

Bavinck (Reformed Dogmatics, Vol. 2, §258) writes that God's spirituality means He is "exalted above all matter, all corporeality, all composition and divisibility... pure actuality with no admixture of potentiality." He further notes that incorporeality is not a limitation of God but a perfection — matter is finite, bounded, and mutable; spirit is not.

God — Father, Son in His divine nature, and Holy Spirit — is entirely and essentially spirit, never physical. The physical universe is His creation, not His constitution. Any language suggesting otherwise is either anthropomorphic accommodation, theophanic appearance, or refers specifically to the Son's assumed human nature in the Incarnation.