Dear Planten,
Happy Eid el Fitr. May your fasting during the Ramadhan be rewarded.
There is no 4 problem of christianity. The problem lies in the illiterate man, trying to copy the teaching of Jesus through the wrong source. No wonder he spread all false things and believe about christianity. Remember the possibility (1) Mohammad did learn to read and write, (2) Mohammad knows christianity from the bishop of Rome, not from Waracca, a nestorian believer rather a true christian, (3) Muhammad take the codices taken from the existing church, rather than taking the apocriph writing (such as copying the psudo-mathew for writing the Mariam story, and claim it as direct words of God), (4) Completing his research that there are much more writings about christianity (the closest was in Alexandria), rather than depending on a limited source and claim it to be from God, (5) Write all of his words himself in one book, so that there is no need for a guy name Utsman to collect all the writings, and burn the original, (6) let the time make a test and not immediately claim his “works” is a dictation from God, so there is no mistake such as 6 or 8 days for the earth creation, mistake in the family of Mary the mother of Jesus, mistake of the Trinity (God, Mary and Jesus).
Well, after that, learning from the “false” things people do, do not make contradictory teaching such as (a) disallowing no object as a resemblance of God, but at the same time reducing God to a brick building that all prayer must be directed to it whereever you are in this world. (b) Teaching that a stone must be kissed, while other “stone” must be stoned and (c) teaching that pilgrimage is pure optional, not a necessity. Oh dear, many Indonesians sell their only property to go to Mecca, being a Hajj, and returning home being broke.