Is there a degree of piety that prevents a person from misguidance thereafter, or is misguidance possible for everyone, no matter how high their degree of piety?

A servant is not safe from deviation and misguidance until death, because he is exposed to Satan and his诱惑 (allure), the influence of bad companions, and the tribulations of the End of Times. Therefore, the servant must seek refuge with Allah and ask Him for steadfastness, just as the Prophet, peace and blessings be upon him, used to supplicate: "O Turner of the hearts, make my heart firm upon Your religion," and just as the early Muslims (Salaf) feared hypocrisy for themselves.