Hawzah News Agency – The merciful prophet of Islam, peace be upon him and his household says:

مَن قالَ: «لا إله إلّا اللَّهُ» مُخْلِصاً دَخلَ الجنّةَ. قِيلَ: وما إخلاصُها؟ قالَ: أنْ تَحْجِزَهُ عَن مَحارِمِ اللَّهِ.

 'Whoever sincerely says: 'There is no god but Allah' (la ilaha illallah) will enter Paradise.' He was asked, 'And where does the sincerity of it [i.e. the statement] lie?' He said, 'In guarding it from what Allah has prohibited.'

Source: Kanz al-Ummal, no. 205