How do we know that we must be converted to enter the kingdom of God?

The necessity of conversion is highlighted in Matthew 18:3, where Jesus says, 'Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven.' This conversion is not something one achieves through personal effort; it is an act of God who transforms the heart of an individual. The term 'converted' implies a change initiated by Christ whereby a person is brought to humility, recognizing their own insufficiency and absolute need for divine grace to be part of God's kingdom.