Is someone who declared the two testimonies of faith with the intention of embracing Islam failed to fulfil their obligations and does not believe in other gods beside Allaah, excused for his ignorance?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

Whoever declares the two testimonies of faith and does not believe in other gods beside Allaah and does not believe in anything that nullifies these testimonies then he has indeed embraced Islam. However, if he commits after that an act of Kufr (disbelief), then we have to look into his situation. If he is a new Islam and was not able to learn the necessary things with which he can protect his religion, or that he lives in a remote countryside where there is no one who can teach other people their religion, then in such a case he is excused for his ignorance, and ignorance is one of the obstacle that prevents declaring someone as a non-Muslim. 

Allaah Knows best.