Tertullian

Tertullian (c.155 - c.220 CE) was an early Christian writer and theologian who defended Christianity, shaped doctrine, and influenced Western theology with his rigorous, often confrontational style. He is known for being the first writer to use the word Trinity in reference to the union between God the Father, God the Son and God the Holy Spirit.

As a prolific writer and theologian from Carthage in North Africa, he was notable for his rigorous defence of Christian doctrine against Roman paganism and secular authority. Tertullian's works, characterized by their polemical tone, sought to challenge and refute the prevailing Roman religious and moral norms, emphasizing a strict, puritanical approach to Christian living that often put him at odds with the established Church.

Tertullian laid the groundwork for what would later be seen as Protestant ideals of reform and ecclesiastical purity, advocating a return to what he saw as the true, unadulterated teachings of Jesus.

He was a huge influence on Novatian and the Novatianists.