When shaytān looks at you and sees you persistent in your obedience to Allah (SWT), he will do his utmost to deceive you; if he still sees you persistent, he will give up on you and leave.  However, if he sees you alternating between this and that, he will have hope in you.

—Al-Ḥasan al-Baṣrī

(Read on pg 39, Ibn Rajab al-Hanbali, The Journey to Allah. Daar us-Sunnah Publishers. Birmingham: 2007.)