The trinity (not the word), but the doctrine, is clearly set out in Scripture. That is why I answered in the way that I did. It is ridiculous to assume that the Apostles were ignorant of the trinity when they believed that there was one God, and at the same time believed the Father, the Son, and the Holy Spirit to be God. That is spelled out in Scripture very clearly.Matt Black said:You're missing the point of the OP and proving my point by your post. To remind you, the OP asked whether there was any church tradition, not explicitly recorded in Scripture, which is a matter of salvation, and which can be traced to the Apostolic Age. The Trinity is a prime example of that: it's not set out in Scripture - although like most Tradition, it can most certainly be inferred from Scripture - but you agree with me that the Apostles knew it.
Furthermore the doctrine of the trinity is doctrine, Biblical doctrine straight from the Scriptures themselves. It is not tradition, has nothing to do with tradition. It is not extra-Biblical, and one would be very foolish to say that it is.