Hawzah News Agency – Imam al-Sadiq peace be upon him says:

إنّ الإيمانَ ما وَقَرَ في القلوبِ، والإسلامَ ما علَيهِ المَناكِحُ والمَوارِيثُ وحَقْنُ الدِّماءِ.

'Verily faith is that which is embedded in the hearts, whereas Islam is the means by which marriages, inheritances and safeguarding blood take place.'

Source: al-Kafi, v. 2, p. 26, no. 3