From Muhammad, the slave, and the Messenger of Allah to Heraclius the Great of the Romans: Peace be upon he who follows the guidance. Furthermore, I invite you with the invitation to peace. If you submit then you will find safety and God will double your reward. If you turn away, you will bear the Arians’ sins.
Disbelieving While Not Realizing: A leaflet translated into French explains the concept of disbelief along with some of its major acts that expel a person from Islam and some prohibited acts and words.
This article in French shows that fasting the six days after Ramadan is an evidence on the fasting person's thanks to his Lord almighty for His easiness of fasting Ramadan, increase in goodness. It is also a sign of loving the righteous deeds and a desire to continue in this righteous path.