Accordingly, Islam also increases and decreases along with faith; as Allah Almighty has said: ﴿وَلَمَّا رَأَى الْمُؤْمِنُونَ الْأَحْزَابَ قَالُوا هَذَا مَا وَعَدَنَا اللَّهُ وَرَسُولُهُ وَصَدَقَ اللَّهُ وَرَسُولُهُ ۚ وَمَا زَادَهُمْ إِلَّا إِيمَانًا وَتَسْلِيمًا﴾[1]; “And when the believers saw the confederates, they said: ‘This is what Allah and His Prophet promised us, and Allah and His Prophet spoke the truth.’ And it increased them in nothing but faith and submission.” Therefore, one who has affirmed and accepted the last Prophet of Allah only in theory is a Muslim. However, more of a Muslim than that person is one who adheres in practice to the requirements of that affirmation and acceptance and is considered a believer—and whoever adheres more to these requirements in practice is considered more of a believer. Based on this, one who has affirmed and accepted the last Prophet of Allah only in theory but does not, in practice, adhere to the requirements of this theoretical affirmation and acceptance is within the fold of Islam and is not considered a disbeliever due to his deed; because one who knows, in theory, about the Prophethood of the last Prophet and the truth of what he has brought from Allah—even if he does not act upon the requirements of his knowledge—is not the same as one who does not know, in theory, about this fact. To consider the two equal is contrary to conscience and what is perceptible; as Allah Almighty has said: ﴿قُلْ هَلْ يَسْتَوِي الَّذِينَ يَعْلَمُونَ وَالَّذِينَ لَا يَعْلَمُونَ ۗ إِنَّمَا يَتَذَكَّرُ أُولُو الْأَلْبَابِ﴾[2]; “Say: ‘Are those who know equal to those who do not know?! Only the owners of intellects take heed,’” and : ﴿أَفَمَنْ يَعْلَمُ أَنَّمَا أُنْزِلَ إِلَيْكَ مِنْ رَبِّكَ الْحَقُّ كَمَنْ هُوَ أَعْمَى ۚ إِنَّمَا يَتَذَكَّرُ أُولُو الْأَلْبَابِ﴾[3]; “Is then one who knows that what has been revealed to you from your Lord is the truth like one who is blind?! Only the owners of the intellects take heed.”

[Recognizing the Sinful Person[4]]

In any case, such a person has submitted to the will of Allah in terms of belief, and it is clear that belief is the foundation of deed; rather, it is considered a type of deed. Nevertheless, if this person does not act upon other rulings of Allah and things that bring about His satisfaction, due to ignorance or negligence, and even performs deeds similar to those of disbelievers, he is technically regarded as a “sinful person” and is not considered a “believer”;