The word Trinity does not occur in the Scriptures, but this is no argument against the doctrine itself, since the Scriptures teach the divinity of the Son and of the Holy Ghost, as well as that of the Father; and as neither the divinity of the Father nor the unity of the Godhead was ever called in question at any period, it follows that the doctrine of the Trinity in unity has been in substance, in all its constituent parts, always known among Christians. The testimony of the fathers is explicit in favor of this doctrine. Justin Martyr, in refuting the charge of atheism urged against the Christians because they did not believe in the gods of the heathen, expressly says: "We worship and adore the Father, and Son who came from him and taught us, these things, and the prophetic Spirit." Athenagoras, in replying to the same charge, says: "Who would not wonder when he knows that we who call upon God the Father, and God the Son, and God the Holy Spirit, showing their power in the unity and their distinction in order, should be called atheists." Tertullian says: "There are three of one substance, and of one condition, and of one power, because there is one God." And he further adds: "The connection of the Father in the Son and of the Son in the Comforter makes three united together, which three are one thing, not one person, as it is said, I and the Father are one thing with regard to the unity of substance, not of the singularity of numbers." And he adds: "The Father is God, and the Son is God, and the Holy Ghost is God." Tertullian asserts that this doctrine was in the Church prior to any heresy. Cyprian says, after reciting the form of baptism: "By it Christ delivered the doctrine of the Trinity, unto which mystery or sacrament the nations were to be baptized."