Imâm Al-Awzâ’î – Allâh have mercy on him – said:

Faith (îmân) is not sound except with [correct] words. Faith and words are not sound except with [good] works. And faith, words and deeds are not sound except with [the correct] intentions in conformance to the Sunnah.

Those who went before us of our Salaf did not separate faith from deeds: deeds are a part of faith, and faith is from [ones deeds]. îmân is a word that brings together these aspects of the religions [of Allâh] and is confirmed through [a person's] works.

So whoever believes in word, knows in his heart and confirms [his belief] through his works, then this is the strongest handhold that will never break. And whoever says [words of faith] but does not know [faith] in his heart nor confirms it with his works, it will never be accepted of him and he will be in the hereafter from those who suffer in loss.

Source:

Ibn Ba tt ah, Al-Ibânah Al-Kubrâ article 1097.