اللهم يا أرحم الراحمين إني قد أودعتك يقيني هذا وثبات ديني وأنت مستودع وقد أمرتنا بحفظ الودائع فرده علي وقت حضور موتي
Fakhrul Muhaqqeqeen also says that those who wish to remain safe from shaitaan's mischief of abandoning faith during death, should recite dua'e Adeelah with a pure mind and heart. (Du'ae Adeelah is found in all the renowned books of du'as, and also in the first volume of Mafateehul Jinaan by the same author).
Shaikh Toosi relates from Mohammad b. Sulayman Daylami that I asked Imam Ja'far-as-Sadiq (A.S.) that, "Some of your faithful followers (Shi'ahs) say that faith (Eeman) is of two types: (1) Permanent & firmly established, and (2) One which has been given to us as a trust, and also can be ruined. Please give me a du'a by which my faith may also become permanent and firmly established." Imam (A.S.) told him to recite the following du'a after every obligatory prayers (Wajib Namaz):
رضيت بالله ربّاً وبمحمد صلى الله عليه وآله نبياً وبالإسلام دينا وبالقرآن كتابا وبالكعبة قبلة وبعلي وليّاً وإماماً وبالحسن والحسين وعليّ بن الحسين ومحمد بن علي وجعفر بن محمد وموسى بن جعفر وعلي بن موسى ومحمد بن علي وعلي بن محمد والحسن والحجة بن الحسن صلوات الله عليهم أئمة اللهم إني رضيت بهم