The phrase "go through fire water" means to undergo a severe trial or ordeal. To express this concept, we can also use phrases such as "brave hardship," "withstand adversity," or "face tribulation." Another synonym for this phrase is "endure hardships," which highlights the idea of persevering through difficulty. Other related phrases include "overcome obstacles," "navigate challenges," and "survive adversity." However it is expressed, the idea remains the same: the act of enduring difficulties and coming out on the other side a stronger person.