الجواب وباللہ التوفیق

Shaytan whispers such thoughts in one’s mind and one should not focus on them. Just through the occurrence of these suspicions in your heart, you would not become sinful. Since these thoughts are involuntary there is no accountability for them either. When you are performing salah, an easy way of getting rid of such thoughts and whispering, is to focus your attention on the step of salah you are performing and concentrate on the tasbeeh and its meaning, with the rememberance that Allah Subhanahu Wa Ta‘ala is looking at you. When you encounter such thoughs outside of salah, you should read the following:

اعوذ باللہ من الشیطن الرجیم آمنت باللہ ورسولہ

And recite the third kalimah in abundance i.e.:

سبحان اللہ والحمد للہ ولا الہ الا اللہ واللہ اکبر ولا حول ولا قوۃ   الا باللہ العلی العظیم

InshahAllah with the above metioned actions, these thoughts and whispering will decrease.

واللہ اعلم بالصواب