Tertullian against Marcion
Let the heretics contrive something of the same kind. For after their blasphemy, what is there that is unlawful for them (to attempt)? But should they even effect the contrivance, they will not advance a step. For their very doctrine, after comparison with that of the apostles, will declare, by its own diversity and contrariety, that it had for its author neither an apostle nor an apostolic man; because, as the apostles would never have taught things which were self-contradictory, so the apostolic men would not have inculcated teaching different from the apostles, unless they who received their instruction from the apostles went and preached in a contrary manner.
To this test, therefore will they be submitted for proof by those churches, who, although they derive not their founder from apostles or apostolic men (as being of much later date, for they are in fact being founded daily), yet, since they agree in the same faith, they are accounted as not less apostolic because they are akin in doctrine. Then let all the heresies, when challenged to these two That is, the succession of bishops from the apostles, and the identity of doctrine with the apostolic. tests by our apostolic church, offer their proof of how they deem themselves to be apostolic. But in truth they neither are so, nor are they able to prove themselves to be what they are not. Nor are they admitted to peaceful relations and communion by such churches as are in any way connected with apostles, inasmuch as they are in no sense themselves apostolic because of their diversity as to the mysteries of the faith.
From this, therefore, do we draw up our rule. Since the Lord Jesus Christ sent the apostles to preach, (our rule is) that no others ought to be received as preachers than those whom Christ appointed; for “no man knoweth the Father save the Son, and he to whomsoever the Son will reveal Him.” Nor does the Son seem to have revealed Him to any other than the apostles, whom He sent forth to preach—that, of course, which He revealed to them. Now, what that was which they preached—in other words, what it was which Christ revealed to them—can, as I must here likewise prescribe, properly be proved in no other way than by those very churches which the apostles founded in person, by declaring the gospel to them directly themselves, both vivâ voce, as the phrase is, and subsequently by their epistles. If, then, these things are so, it is in the same degree manifest that all doctrine which agrees with the apostolic churches—those moulds and original sources of the faith must be reckoned for truth, as undoubtedly containing that which the (said) churches received from the apostles, the apostles from Christ, Christ from God.
Whereas all doctrine must be prejudged as false which savours of contrariety to the truth of the churches and apostles of Christ and God. It remains, then, that we demonstrate whether this doctrine of ours, of which we have now given the rule, has its origin in the tradition of the apostles, and whether all other doctrines do not ipso facto proceed from falsehood. We hold communion with the apostolic churches because our doctrine is in no respect different from theirs. This is our witness of truth. Tertullian against Marcion
A good study of sound orthodox doctrine is reading the early church fathers those that were taught by the disciples and Apostles of the Lord. The writings of Justin Martyr the first Christain Apologist and Irenaeus are good books to read concerning doctrine of the church during and after the apostolic age. In fact if you read the liturgy written by James, who first received the episcopate of the church at Jerusalem from the Saviour himself that James was appointed bishop of Jerusalem by Christ himself was an old and wide-spread tradition.and the apostles, and who, as the divine records show, was called a brother of Christ, it is quite similar to what is being used in the church todday.
Also searcgh on the writings of Flavius Josephus for the Jewish/Roman War.
An excellent collection of the writings of the early church fathers can be found at:
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ccel.org/fathers.html**