“That’s how God made me” is a statement that can be very freeing, or completely enslaving. Like it’s reverse, “That’s not how God made me” it can make your life far better or much worse. Both sentiments can also make the lives of those around you better or worse.
There are things about us that are innate; they are who we are, they are how we are made. Either we can’t change those things or can’t change them without doing deep harming to who we are. Things, like being an introvert or being optimistic, are personality traits we can’t change by force of will. When we accept these things as part of who we are, we can stop worrying about them, beating ourselves over them, wasting time trying to change them, or being harmed by those who want us to be different.
On the other hand, some folks use this idea to try and excuse themselves from being decent people. They want to believe being rude, grumpy, pushy, or always exaggerating are how God made them; giving them an excuse not to change. Folks who do this are difficult to be around because their unloving/bad behaviour continues unchecked and without remorse.
It can be tough to decide what’s “how God made me” and what’s not, but the Bible gives us some help on this:
But the fruit of the Spirit is love, joy, peace, longsuffering, kindness, goodness, faithfulness, gentleness, self-control. Against such there is no law. And those who are Christ’s have crucified the flesh with its passions and desires. If we live in the Spirit, let us also walk in the Spirit. Let us not become conceited, provoking one another, envying one another. [Gal 5:22-26 NKJV]