A religion's commandment. No one can prove that it was god who commanded it. But we can prove for certain that a religion commanded it.
We believe in angels. We believe in shaytan and Jinns. U told us u saw a spirit. But to us Muslim, tat aint no spirit. Its the work of jinn. We have also discussed in very detail in the existence of Allah, the Prophet and the Quran is the word of God. Refer ur PM. I had even show u 10 evidence why the Quran is the word of God as wats mentioned in the Quran tat had been proven by present scientist. But u did not rebuke those 10 evidences one by one. Tats only the Quran. Now i also have evidence (prediction) by the Prophet s.a.w. in the hadiths, which came true too. I bet u also have no answers for it.