One of my dear friends has five adult children. They are all doing well in life now, all walking with God. But she said, "When they were young, one of them was so naughty! I think I disciplined him every day until he was twelve. There were mornings he would get up, and I would think, 'Might as well get the discipline out of the way now, because we both know you're going to need it today!'"
I have five children, too. And they are not all equally compliant. If I had only the children who were less compliant, I might feel like a pretty incompetent parent! But with five, I can see that, yes, some personalities are, indeed, more challenging.
If that discourages me (and it does sometimes), I think, "None of my children have been disciplined every day until age twelve," and then I feel better. At least a little bit.
Or if we have dealt with a long stretch of naughty behavior, I think, "My friend's son was super naughty growing up, but look how well he turned out! Persevere!"
It is also helpful for me, at times, to step back and really look at my children. My oldest always seemed so old, since the second baby came along pretty quickly. But an old-looking three-year-old is still . . . just three.
Or if a ten-year-old behaves badly, I shouldn't think, "Clearly you are on the path to perdition and all is now lost!" No. Ten is still young. Old enough to know better? Of course. But still learning? Yes!
As old as I am, and as honestly as I seek to follow God, I am not perfect. I have received much grace. And much gentle correction. And sometimes stern correction.
Extend to your children that same grace, forgiveness, gentle correction, and occasional stern correction.
"Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up." (Galatians 6:9)
John and Sarita's oldest daughter
Homeschooling mom to five
P.S. Just because one child is more obedient from the get-go doesn't mean that they will not later struggle, nor does it mean that the one you are struggling with now will always be disruptive.
Children have different personalities, and the Lord uses all of these for his glory. Jesus made both firecracker Peter and milder Philip as part of his inside circle, and they both served him and advanced the kingdom of God.