When you're playing the "typing" or "pick a word" game, the motivation to avoid mistakes and the excitement of pick the right word/letter is greatly limited by the fact that making a mistake has no impact on the game whatsoever. Sometimes I find myself spamming random letters instead of taking the time to try and remember the correct word.
It doesn't need to immediately restart the whole verse/passage, but at least give me some intense haptic/visual feedback (e.g. screen shaking) and give me an accuracy percentage at the end. This would also greatly improve the perception of progress: As I memorize verses better, the accuracy percentage goes up and I am able to go through the verse faster and faster.
Maybe you could even add a toggle for a hardcore mode that resets the whole passage after one mistake with a timer to see how fast you were. Or add an option to move back one word for every mistake made.