Is doubt and suspicion in religion, resulting from the whispers of Satan, considered apostasy from Islam?

The believer must blame himself, not his Sharī‘ah (divine law), if he does not attain the promised reward and benefit. Supplication (Du‘a’) is a weapon wielded by its user, and its delayed effect may be due to the supplication itself, or the supplicant, or the presence of an impediment such as heedlessness or doubt. Whoever finds such doubts within himself should strive against them, for they are from the whisperings of Satan. One must differentiate between whispering (waswasah) and doubt (shakk) that expels one from the faith. Whispering attacks the heart and is disliked by the servant, whereas doubt is hesitation and the opposite of certainty. The meaning of Allah Almighty's saying, {And whoever turns away from My remembrance – indeed, he will have a restricted life, and We will gather him on the Day of Resurrection blind} (Taha 20:124), is that whoever disobeys Allah Almighty's command will have a narrow life in this world and an anxious soul, even if he appears to be in comfort, and he will be gathered on the Day of Resurrection blind to the proof.