Short Answer 
The metaphor of a mountain in Isaiah represents a divine banquet for the faithful, reflecting the joys of the Kingdom of Heaven. Isaiah promises comfort after death, paralleling New Testament teachings on Christ’s victory over death and the rewards for those who remain faithful to God.
Step 1: Understanding the Metaphor of the Mountain
In the referenced verse, the prophet Isaiah uses the metaphor of a mountain to convey a significant message. This mountain symbolizes a great banquet prepared for God’s chosen ones at its summit. It illustrates the delights awaiting the faithful as a reward for their devotion. This concept is echoed in the New Testament, particularly in Luke’s Gospel, where Jesus similarly invites the faithful to enjoy the joys of the Kingdom of Heaven.
Step 2: The Promise of Divine Comfort
Isaiah further emphasizes that God will provide comfort to his chosen ones after death, indicating that they will no longer experience pain or suffering as they did on Earth. This assurance is parallel to the teachings in Corinthians, where it is stated that Christ will triumph over all adversaries and reign eternally in the Kingdom of Heaven. This reign offers believers the hope of conquering death, just as Jesus did.
Step 3: The Reward of Faithfulness
Both Isaiah and the New Testament highlight the benefits of faithfulness to God, suggesting that those who remain devoted will receive profound rewards. Key points include:
- The invitation to a divine banquet for the faithful.
- The promise of eternal comfort without pain in the afterlife.
- The victory over death through faith in Christ.