Kai,
Q4:171 is widely held by Muslims as the strength of their argument to mainstream Christianity belief of the true God; Instead, is nothing more than same inadequate Quranic definition of trinity. However, from your argument, some Muslims will mistakenly gather you are defending a Maryamite belief. Here, I please ask you take a few minutes to read Sam Shamoun's article http://answeringislam.org.uk/Responses/ ... /t5_73.htm Peace be with you.
joseph