Christianity for example has lasted more than 2000 years. On what basis then do you say that it won't be around in the next 1000 years?
Egyptian gods were worshiped for a few thousand years. Now gone. Greek gods. Now gone. Old Norse religion. Gone. Semitic religion. Gone. Mesopotamian religion. Gone. Babylonian. Gone. Celtic polytheism. Gone. Etc. Etc. Etc.
The number of extinct religions vastly outnumbers the number of practicing religions. On what basis then do you say that Christianity will still be around in 1000 years, especially since we are proving more and more of Christian doctrine demonstrably false?