Any individual would know without doubt that he would be burned if he stuck his hand into a fire. He would never have to think whether it was really going to get burned or not. This means that this person has the implicit belief that the fire is going to burn his hand. In the Quran, “implicit belief” is referred to as follows: 
This (the Quran) is a clear insight for mankind, and guidance and a mercy for people who believe with certainty. (Surat al-Jathiyyah: 20)
“Having implicit faith” means believing in Allah’s existence and uniqueness, the day of resurrection, heaven and hell with absolute certainty, without any doubt, with full confidence as to their truth. It is like believing in the existence of the beings around one, whom one sees and talks to, and the intuitive knowledge demonstrated by the example of the fire given above. Faith built on believing with certainty develops in the individual a conscience which will prod him into spending every moment of his life acting in a way that will please Allah.