I never really thought of it as religious undertones. They were often pretty clear to me. As others have already mentioned, there are plenty of other anime series that have religious references and syrabolism besides the Digimon series. Yu-Gi-Oh! and Fushigi Yugi are the first ones that I think of off the top of my head. I agree with those who have said that they just add these references because of how cool it looks like.
As for the Digi-eggs, I never really saw it as being simular to reincarnation. Although Digimon that are destoryed in Adventure 01, 02, Froniter and Savers/Data Squad were reborn, they pretty much remerabered everything from their lives beforehand. The only exceptions were in Savers/Data Squad and Tamers since the idea of being reborn never came up in the series.
As for the Digi-eggs, I never really saw it as being simular to reincarnation. Although Digimon that are destoryed in Adventure 01, 02, Froniter and Savers/Data Squad were reborn, they pretty much remerabered everything from their lives beforehand. The only exceptions were in Savers/Data Squad and Tamers since the idea of being reborn never came up in the series.