The binding nature of the actions of the heart is stronger than that of the acts of the members. This is why Ibn Al-Qayyim says: ' He who disagrees with the sources and origins of the legislation will know the connection of the actions of the members with those of the acts of the heart, that they are useless without them. What differentiates the believer from the hypocritical, if not what is in the heart of each one as acts that distinguish them? Can anyone enter into Islam without acts of the heart that precede those of its members?
As the Imams say: "Words and deeds, inner and outer words, internal and external acts." When the inside is virtuous, the outside will be, and if it is corrupt, the outside will follow."
Majmû ' al-fatâwâ (7/187)