Thank you for your question. The problem with many questions such as this is that they are not usually framed realistically. Is it really realistic for someone who does not believe in the religion of Islam to perform all of his or her actions according to its dictates? If that is not possible or unrealistic then this question is completely hypothetical. God will ultimately judge every person, but the value of being in the fold of Islam is such that in this hypothetical situation the Muslim will have a better end as the Prophet (saw) will intercede for the major sinners in his community, if they have the capacity to be interceded for.
May you always be successful
May you always be successful.