(Prescription against her., 34, Tertullian)These are, as I suppose, the different kinds of spurious doctrines, which (as we are informed by the apostles themselves) existed in their own day. And yet we find among so many various perversions of truth, not one school which raised any controversy concerning God as the Creator of all things. No man was bold enough to surmise a second god. More readily was doubt felt about the Son than about the Father, until Marcion introduced, in addition to the Creator, another god of goodness only.
What did Tertullian mean with the words "doubt felt about the Son" before the marcionite heresy?
If we link the marcionite boom with the first great PUBLIC diffusion of a written gospel in the Christian world (the first time when a written Gospel becomes a best-seller, and not the first time when a Gospel was written), then Tertullian is saying that before the common knowledge of that best-seller, the problem of the problems was not the nature benevolent or malevolent of the creator god, but the nature of the Son: was he a real man?
Said otherwise: did he exist?
Marcion was the first famous Jesus-literalist (not the first euhemerizer). With him the polemic was moved for the first time from the question of the historicity of the Son to the question of the identity of the true God.