Jesus told us what to do - go and spread the gospel.
Yet, they have seed.
Their offspring have no resurrection. The angels were banished to the lowest depth of Hell.
Right, for crossing 'kinds'. Edenic law says everything according to kind... Their bastard children have no part in the resurrection because they are outside of YHWH's design.
That does imply angels having natural children - those who did not 'leave their first estate'. Angels have seed. Seed has purpose.