The first great Latin theologian
A Carthaginian lawyer turned Christian writer, Tertullian gave the Western church much of its theological vocabulary — including the Latin word trinitas (Trinity), and the formula "three Persons, one Substance" that the later creeds would refine. He wrote roughly a century before the Council of Nicaea, which is why he matters so much in any argument about whether the Trinity was a fourth-century invention.
His prose is combative, quotable and merciless toward what he considered compromise. "The blood of the martyrs is the seed of the church" is his. So is "What has Athens to do with Jerusalem?" — his challenge to Christians who wanted to domesticate the faith into Greek philosophy.
What baptism means, why Jesus commanded it, how the first Christians practised it, where churches differ on mode and on infants, whether it saves, and how to prepare — including what it means to be baptised as a public break with old allegiances.
The doctrine that distinguishes Christianity from every other monotheism: what it claims, what it does not claim, how Scripture builds it, and why it is not a contradiction.
Where 25 December really came from, why Easter is tied to Passover, what the word "Easter" means — and what to say when someone tells you your feasts are borrowed from idolaters.
House churches before dawn, shared meals, baptism in running water, care for widows and abandoned babies — what ordinary Christian life looked like in the first three centuries, and why Rome called them atheists.
From twelve frightened men to the official faith of the empire in three centuries — the roads, the martyrs, the plagues, the strategy and the emperors that made it happen.
Ethiopia, Egypt, Nubia, Persia, India and China had established churches centuries before most of Europe. The strongest answer to "Christianity is the white man's religion".
How many Christians face persecution, who is doing it and why, what is actually happening in Nigeria, North Korea, China, India, Iran, Afghanistan and Eritrea — and how to pray and help without spreading rumours or hatred.
Tracing the doctrine through Scripture and the pre-Nicene church — with the documentary evidence that ends the "invented at Nicaea" claim.