What’s the best way to avoid sinning?
My short answer is built into the question: avoid it.
That sounds almost too obvious, but it changes the focus. Instead of relying only on willpower in the moment, I can look at what keeps putting me in that moment, and change it.
I can cut off contact with a person or situation that repeatedly leads me toward wrongdoing. I can change my environment. I can give up something I like if it’s becoming a path to sin.
And that's the practical lesson I draw from Jesus' words in Matthew 18:6–9.
Of course, not every temptation can be removed. When I can’t avoid it, I still have to resist it; and that can be harder. But I believe God can give us the grace and strength to say no.