Um, it was God that arranged it for him to be born as a Buddhist. I don't think Christ will have too much a problem with his own arrangements.
Free will remember? He has certainly heard of Jesus and knows his message. Still given that he and all his co-religionist are emmersed in Buddhism, have been taught all thier lives that it is the right way and proper way to live, one would not expect that such conditioning is not easy to surmount.
There is no doubt in my mind that I would very likely be and remain a loyal Buddhist, Jew or Protestant if I had been born into any one of those faiths.