Are there any nullifiers that invalidate the protection afforded by ذكر (remembrance of God)?

The remembrance of Allah protects the servant from devils and has immense benefits in this world and the Hereafter, as mentioned by Ibn al-Qayyim. The effect of remembrance varies according to the faith of the one remembering and the presence of his heart. Supplications and seeking refuge are like weapons, and their effect depends on the strength of faith and reliance of the one who utters them. Sins may prevent the effect of remembrance from providing protection, just as they prevent the answering of supplication.