Re: Non Muslim guppies!
God does what he wants - He doesn’t need our approval. Bear this in mind. And yes, when Hazrat Isa’s (Jesus) :as: message lost its significance among the people, it needed renewal. Once Hazrat Muhammad’s :saw: prophethood was decleared, his message repleced the previous ones. It’s in Quran, “Wa radeetu lakumul islamaa deena!.” This was the last revelation to Hazar Muhammad :saw: before his :saw: passing away.
If anyone wants salvation, he/she should become a Muslim before he dies. Otherwise, there would be no hope.