If you refused to kill your firstborn, you wouldn’t be smitten with a thunderbolt, you’d be told you had passed the test, and were truly worthy.
If this is so, then I have to question why Abraham got the same response for not refusing to kill the first child resulting from his marriage.
In fairness to Christianity, I feel like I ought to point out that according to the Gospels, Jesus didn’t use those powers to make his life more comfortable. Not only do we not see any instances of him doing this (at least, I don’t recall any, and it doesn’t fit with my understanding of the New Testament; if anyone does have a counterexample, then that would be welcome), the Temptations show him actively refusing to use his supernatural abilities for selfish purposes, even harmless ones like feeding himself. (To clarify, I don’t believe he had any supernatural abilities to begin with, but I feel like it’s worth mentioning).