Narrow door or narrow gate connected to repentance
Jesus is saying to this questioner, “Repent. Enter through the narrow door, through the narrow gate, for there are so many people who claim to know God, there are so many people who claim to follow God, there are so many people who claim to have a relationship with God, but if you have not repented you don't understand your fundamental problem, you don't understand the provision of the Lord in Jesus Christ for your sins, you have not responded in the way that everyone must respond to Jesus’ message who will be saved.”