Mormon missionaries are easily identified. They go in pairs, wear white shirts, dark trousers, name tags (“Elder ___” or “Sister ___”), usually White Americans, etc. It’s their version of National Service. Today I saw a pair of those. I guess they keep the practice of sending missionaries in pair to follow the biblical pattern when Jesus sent out his disciples to proclaim the advent of the kingdom of God. Why in twos, then? Well, psychologically, going in pair really helps since they could support each other. Theologically, I think it was based on the understanding of lawful testimony in the Torah: “One witness is not enough to convict anyone accused of any crime or offense they may have committed. A matter must be established by the testimony of two or three witnesses.” (Deu 19.15, see also 17.6) Jesus and Paul followed this injunction as well elsewhere (Jesus: Mat 18.16, Paul: 2 Cor 13.1). And I think that’s the reason, I guess, Luke put two angels in the tomb of Jesus instead of one, as in Matthew and Mark (Luk 24.4, cf. Mat 28.2, Mrk 16.5). In the Gospel of John, there was no angel altogether. Instead, we find Peter and “the other disciple” running to the tomb (Joh 20.3).