When Allah's Messenger (may peace be upon him) asked about the essence of faith, the angel Gabriel replied: faith is you believe in God, His angels, His books, His apostles, the Last day, and qada / good or bad.
The Qur'an further specifies what it is obliged to believe: the Apostle has believed in the Qur'an that was revealed to him from his Lord, as well as those who believe. All have faith in God, his angels, his books and his apostles. (They say): "We do not discriminate between anyone (with others) from His apostles" (Surah 2:85).
To prove the truth of faith or not a person, then the verbal pronunciation must be accompanied by confidence in his heart and expressed by arkan (rukun-rukun). If this is proved to be in a person's person then the person is declared a mu'min (believer).
The Qur'an denied those who proclaim faith in the mouth alone while their hearts disbelieve. (Surah 2: 8). The Qur'an also states about the behavior of Bedouins. Described in the Qur'an: The Bedouin Arabs say: "We have believed". Say: "You have not believed, but say 'we have submitted', because that faith has not yet entered your heart (Qur'an 49:14).
It is true that the invisible and oral utterances are sufficient to convince human beings. This is certainly only applicable in the world, as in Akherat certainly not that easy, then the verbal pronunciation must be included in the heart of faith as well as applied with the implementation of worship with limbs (aljawarih). The worship includes "pure worship" (prayer, zakat, fasting, pilgrimage etc.) and "pure worship" (please help, do good to others, give compensation, etc.).
True faith in God has a positive impact on human life and on his own guidance. Proven Qur'an states: "... and whoever believes in Allah will surely give instructions to his heart". (Surah 64:11).
Those who believe in Allah have enough to bring their adherents into the promised Heaven even though he has a vengeful life. "No is a servant who says There is no god but Allah and he dies over (his) conviction, but he enters Heaven", so the Prophet said. Then friend, Abu Zar Algiffari, asked: "If he commits adultery and steals?" Answer the Messenger of Allah, "even if he commit adultery, even if he stole".
What a wonderful Islam God has given us. Therefore, there is no reason for God's servants to be grateful for the great blessings by constantly praying, asking forgiveness of Allah Almighty. for all the sins and oversight that had been holding his grace. Wallahu a'lam. []