Luke 1:4
Luke 1:4 (Free Bible Version, FBV)
I have done this dear Theophilus so you can be certain that what you were taught is completely reliable.
so you can be certain of the truth of everything you were taught.The Birth of John the Baptist Foretold
so that you may know the exact truth about the things you have been taught. John the Baptist’s Birth Foretold
That thou mightest know the certainty of those things, wherein thou hast been instructed.
that thou mightest know the certainty concerning the things wherein thou wast instructed.
so that you may know the exact truth about the things you have been taught [that is, the history and doctrine of the faith].Birth of John the Baptist Foretold
[My purpose is] that you may know the full truth and understand with certainty and security against error the accounts (histories) and doctrines of the faith of which you have been informed and in which you have been orally instructed.
That thou mightest acknowledge the certaintie of those things, whereof thou hast bene instructed.
People have already taught you about these things. Now you can be sure that they are true.