Well consider this:
1900: ~99% christian, 0.61% jewish, 0.02% muslim, ~0% hindu, N/A atheist
1950: 94% christian, 0.79% jewish, 0.39% muslim, 0.08% hindu, 5.1% atheist
2000: 72% christian, 0.48% jewish, 3.1% muslim, 0.97% hindu, 22% atheist
2025: 46% christian, 0.50% jewish, 6.5% muslim, 1.7% hindu, 37% atheist
now estimated:
2050: ~30% christian, 0.00% jewish, 17% muslim, 3% hindu, ~50% atheist