Exegesis:

oude gar apothanein eti dunantai ‘for they also cannot die any more,’ stating the reason why there is no marriage in the age to come. oude suggests correspondence with what precedes. dunantai means that dying has become impossible.

isaggeloi gar eisin ‘for they are like angels,’ explaining why they cannot die.

isaggelos ‘like an angel,’ substantive.

kai huioi eisin theou, tēs anastaseōs huioi ontes ‘and they are children of God, being children of the resurrection.’ huioi theou refers to a relationship with God which goes beyond the relationship with God in this life. For the phrase tēs anastaseōs huioi cf. on 10.6; here huioi means ‘belonging to,’ ‘sharing in.’ ontes is causal participle.

Translation:

They are equal to angels, or, specifying the point of comparison, ‘they exist like angels,’ ‘they live on like angels do.’

Sons of God, or as a simile, cf. on “sons of the Most High” in 6.35.

Being sons (or, children) of the resurrection. This metaphor, even if marked as a simile, is unacceptable in many languages; hence such renderings as, ‘because (they are) heirs of the resurrection’ (cf. Balinese), “because they have been raised from death” (Good News Translation), ‘because they (are) people who have-been-brought-to-life again, or, have risen from the dead’ (Toraja-Sa’dan, Dan).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.