There are eight prerequisites to the great Phrase 'la ilaaha illa-Allaah'. Every person who declares this phrase should fulfill the following preconditions and to achieve the benefits from Allah on the Day of Judgment.
It will also cause to save him from the Hell-Fire, as well as to win the Pleasure and Love of Allah and admission to Paradise.These preconditions are as follow:
(i) To acquire the necessary knowledge about the phrase 'la-ilaaha illa-Allaah' and to learn it is compulsory.
فَاعْلَمْ أَنَّهُ لاَ إِلَهَ إِلاَّ اللَّهُ
"So know that there is no deity worthy of worship in truth but Allah."
[Surah Muhammad 47:19].
The Prophet Muhammad (swalla-Allaahu alayhi wa-sallam) said,
« مَنْ مَاتَ وَهُوَ يَعْلَمُ أَن لاَّ إِلَهَ إِلاَّ اللهُ دَخَلَ الْجَنَّةَ »
“Whoever dies after knowing that none has the right to be worshipped but Allah, will enter Paradise.”
[A Hadith related by Muslim (26) on the authority of 'Uthman bin 'Affan].