When you pray concentrate on what you are reading. Pray with full focus on the hearse after paradise and hell fire and how you can avoid it and work hard to be in paradise.
You are stronger than Shaitan. Shaitan can only whisper, he has no other means to influence your thoughts. Thus do not sit idle and always occupy yourself with something useful such as studies, remembrance of Allah, recital of Quran, watching documentaries, watching Islamic movies or nohas. Bottom line do not surrender to such thoughts.