that thou mightest know the certainty concerning the things wherein thou wast instructed.

So that you might have certain knowledge of those things about which you were given teaching.

δια να γνωρισης την βεβαιοτητα των πραγματων, περι των οποιων κατηχηθης.

That thou mightest know the certainty of those things, wherein thou hast been instructed.