Because I believe in the Trinity, unlike Unitarians such as yourself. We Trinitarians consider Christ to be God. Unitarians deny the divinity of Christ. That is incorrect. Christ was God — why would you believe otherwise?
What is a Unitarian?
Today, most Unitarian Universalists do not consider themselves Christians, even if they share some beliefs quite similar to those of mainstream Christians. Universalists believe in a loving God.
To a fundamental Christian, a Unitarian is a heretic who has rejected Jesus as the only "way, the truth and the light". A Unitarian on one hand says that Jesus is the greatest teacher. But Unitarians are blinded to His teachings. Jesus said "I and the Father are One". And, Jesus also taught John 14:6 Jesus said, "I am the Way and the Truth and the Life.
To a Christian, a Unitarian seems like someone who can never make up their mind about anything. One of their claims is that they are Unitarians so not to be led into errors by the "teachings of men". But, in remaining outside Christianity, and truly grasping the teachings of Jesus, they fall into the same trap they propose to be hiding from --being misled by men who teach them false doctrines. The Unitarians reject the doctrine of eternal damnation, the Trinity (triune God), and the divinity of Jesus. Universalism is the theological doctrine that all souls will ultimately be saved and that there are no torments of hell.
As a unitarian, do you by default believe in universalism?