John Gill discusses the teachings of Justin Martyr, emphasizing God's eternal prescience and predestination. Justin asserts that God foreknows the choices of individuals regarding faith and repentance, and that salvation is prepared for some while others face judgment due to their own choices. He clarifies that God's foreknowledge does not compel individuals to sin, and that all have the opportunity to seek God's mercy. Justin's writings highlight the elect as a chosen people from all nations, reinforcing the idea of divine selection and grace. This sermon underscores the balance between God's sovereignty and human free will.