Sir Edmund Hillary was the first person to conquer Mount Everest (along with his Sherpa helper Tenzing Norgay) but he didn't beat it on his first try. His first attempt was a failure. But after that failure, he said, "I will come again & conquer you, because as a mountain you can’t grow, but as a human, I can.”
Think about that spiritually. Satan is a powerful and huge, like Mount Everest, but like Everest, he also can't grow. His fate has long been sealed. His bag of tricks is supernaturally powerful but also utterly revealed by God. Now consider what God says about us. "Like newborn babies, long for the pure milk of the word, so that by it you may grow in respect to salvation." (1 Pet 2:2)
Unlike Satan, we CAN grow. Unlike Satan, we CAN be destined for perfect glory. And unlike Satan, we have a Tenzing Norgay on our side of unfathomable power. The only way we can lose is if we don't try.
"For the entire Law is fulfilled in in this one word: "You shall love your neighbor as yourself."—Gal 5:14