Does merely seeing an original disbeliever praying necessitate a ruling on his Islam, and what about the apostate who declares his disbelief and is then seen praying? And is prayer alone sufficient to rule on one's Islam without the two Shahadas?

Scholars have differed regarding the ruling on the conversion to Islam of an apostate or an original disbeliever through prayer. The majority validate this, though they differ on distinguishing between the land of disbelief and the land of Islam, or between individual prayer and congregational prayer. However, if an apostate denies an obligatory act or rejects a pillar of faith, or insults a prophet, merely performing prayer is not sufficient to rule on his conversion to Islam until he repents and affirms what he had denied.