John 5:46

εἰ γὰρ ἐπιστεύετε Μωϋσεῖ, ἐπιστεύετε ἂν ἐμοί· περὶ γὰρ ἐμοῦ ἐκεῖνος ἔγραψεν

For if you all believe in Moses, you would also believe me because/for he wrote about me


 * εἰ ... ἂν construction indicates a 2nd class conditional, a contrary-to-fact conditional in which the protasis (if....) is presumed to be false for the sake of argument.
 * ἂν is in the apodosis to indicate a sense of the hypothetical or contingency.
 * Thus Jesus is implying "you all" likely don't believe in Moses....
 * ἂν is in the apodosis to indicate a sense of the hypothetical.
 * ἐπιστεύετε is imperfect 2P pl. But in the second occurence, when translating into English, we use extra words to indicate the sense of contingency carried by the ἂν. For example, "you would believe".
 * ἐπιστεύετε Μωϋσεῖ - ἐπιστεύετε takes a dative, in this case Μωϋσεῖ.
 * ἐμοί, ἐμοῦ - e- forms for emphasis and common after prepositions.
 * ἔγραψεν - plain old aorist