Why is it important to respond to God's call now?

The urgency of God's call is encapsulated in Isaiah 1:18, where the Lord says, 'Come now.' This urgency indicates that sinners should not delay seeking the Lord, as salvation is available today but not guaranteed for tomorrow. The Lord's call to come is a call to immediate action, highlighting the necessity to recognize our sinful state and His offer of grace. Ignoring this call can lead to dire consequences, as emphasized in verse 20, which warns of judgment for refusal and rebellion against God.