what does the bible say?
Binitarianism, in contrast to Trinitarianism, teaches that God exists as only two Persons—the Father and the Son, with the Holy Spirit being Jesus. This view often misuses Romans 8:9 and appeals to The Shepherd of Hermas, a second-century work that the church never accepted as Scripture and which contains multiple theological errors. Romans 8:9 calls the Spirit “the Spirit of God” and “the Spirit of Christ,” but this describes His ministry, not His identity. The Holy Spirit is called the “Spirit of Christ” because Jesus promised to send Him, He testifies about Christ, and He applies Christ’s work to believers (John 14:26; 15:26; Ephesians 1:13).
Scripture consistently presents the Holy Spirit as a distinct divine Person. In the Old Testament, the Holy Spirit was active in believers’ lives, but the main difference between His presence in the Old Testament is that He infilled rather than permanently indwelled God’s people (Exodus 31:2-5; 1 Samuel 10:10, 16:14). Jesus speaks of the Spirit as “another Helper” whom He will send from the Father (John 14:16; 15:26). The Spirit teaches, guides, convicts, speaks, and wills—actions of a personal agent, not an impersonal force (John 16:13; Acts 13:2; 1 Corinthians 12:11). He can be lied to (Acts 5:3), grieved (Ephesians 4:30), and directs the church’s mission (Acts 13:2–4). These passages show that the Spirit is fully God and personally distinct from the Father and the Son.