Anas bin Malik relates that the Holy Messenger Muhammad (peace and blessings of Allah be to him) said: There are three qualities; whosoever have them may taste the sweetness of faith: first, one who loves Allah and His Messenger above all else; secondly, one who loves someone simply for the sake of Allah; and thirdly, one who abhors return to disbelief after Allah has rescued him from it, as he abhors being thrown into the fire (of hell). (Bukhari, Muslim)
Man wants to submit himself to and love a Supreme Being. The hadīth puts this submission and love in the right order: one who loves Allah and His Messenger more than everyone else, and loves someone else simply for the sake of Allah can taste the sweetness of faith. His heart lights up with faith and he stands steadfast.
A man loves his parents, wife and children. If his parent asks him to do something un-Islamic, his love for Allah prohibits him. If he listens to the call for Prayers, his love for Allah comes to light. The Blessed Messenger was the best husband to his wives. But, on listening to the call for Prayers, he used to rush to the mosque as if he had nothing to do with them. If a man sees his child doing something un-Islamic, his love for Allah prompts him to reform the child.
Another important quality is that when one changes over to Truth from falsehood, one should not backtrack rather stick to one’s gun however sufferings he may have to bear.