1 Corinthians 10

10 And do not grumble, as some of them did—and were killed by the destroying angel. 11 These things happened to them as examples and were written down as warnings for us, on whom the culmination of the ages has come.
When I complain or become angry about an injustice, it can be sign of entitlement that I believe life should go towards my own self interest. If I get used to this entitlement I'll be relying on how convenient life is for me rather than God, i'll be taking His blessings for granted just like how the Israelites did when they left Egypt. What makes the Bible so important for me and millions of others today is over the estimated course of possibly 4000 years we have studied stories of triumph and collapse of God's chosen people. These lessons remind me of how much I fall short to God's standards and why I so desperately need him.

23 “I have the right to do anything,” you say—but not everything is beneficial. “I have the right to do anything”—but not everything is constructive. 24 No one should seek their own good, but the good of others.
Nothing which in which I should do should cause another believer to stumble, much rather I should do what's best for them in order they might be saved. Having a single mind for Christ creates more awareness in how our words or actions can affect others, and certain limitations are necessary for certain people so that there'll be no misunderstanding and not lose their way.