How do we know that God's grace cannot be resisted?

In the context of sovereign grace theology, it is understood that when God’s regenerating grace is bestowed upon an individual, they cannot resist it. The teaching is based on the biblical concept that spiritually dead individuals lack the capacity to respond to God on their own. Ephesians 2:1 illustrates this by stating that we were once dead in trespasses and sins. Only when God quickens the heart does a person become alive to respond in faith. This aligns with the doctrine of TULIP, specifically the 'U' for Unconditional Election, where the elect respond to the gospel because God has chosen to awaken their hearts, thus making resistance an impossibility.