Answer:
The personification can be found in the phrase "There is hell's wide gaping mouth open". The function of this personification is to affirm that the human being is always one step away from entering hell and there is nothing, except God, to prevent this.
Edward's goal was to show people that everyone is a sinner and so they are not free from going to hell. When he says that the mouth of hell is wide open, he means that hell is waiting for all of us, but only God can get us out of there.
Explanation:
Personification is the figure of speech that allows inanimate objects to have human characteristics.
As we know, hell is not a living being, it is not a human being and therefore has no mouth. However, in the text above, we can see that Edward claims, that hell has its mouth wide open and that there is nothing we can do to prevent us from falling into it.
Edward uses the term "mouth of hell" to represent the gates of hell. He wants to tell his audience that the door to hell is open to sinners and there is nothing that can be done to keep them from going to hell. If we are sinners, we enter through that door and only God can prevent it.