How do we know God's grace is available to all sinners?

In the narrative of Jonah, we see God's initiative in extending grace, as He sent Jonah with a message that resulted in the Ninevites' repentance. This highlights that God's grace is not reserved for the deserving but is freely given to the unworthy. Romans 5:8 reinforces this by stating that 'God demonstrates His own love toward us, in that while we were still sinners, Christ died for us.' Each believer can rest assured that no matter how sinful they perceive themselves to be, they can approach God with confidence, knowing that He delights to show mercy and will not cast them out if they come to Him (John 6:37).