How can I be sure that my wife won divorce me for no good reason?
There’s no such thing as “no good reason”, everything happens for a reason, and if she divorces you, it’s for a good reason. I think that if you’re concerned now that she’ll divorce you, then there are obviously problems you need to work out. I would suggest sitting down and talking honestly and frankly about your concerns. Look into marriage counseling, it helps sooo many people and it’s the best thing for many. In the meantime, be a good man, live a good life, and treat her like the queen she truly is.
