Biblical Reference:
The phrase "A House of Prayer for All Nations" is primarily derived from the book of Isaiah and is echoed in the New Testament. The key scripture is Isaiah 56:7, which states: "I will bring them to My holy mountain and make them joyful in My house of prayer. Their burnt offerings and sacrifices will be accepted on My altar; for My house will be called a house of prayer for all the nations."

Context in Isaiah:
Isaiah 56 is a prophetic chapter that emphasizes the inclusivity of God's covenant. It extends the promise of blessing and acceptance to foreigners and eunuchs who join themselves to the Lord, keep the Sabbath, and hold fast to His covenant. The declaration that God's house will be a "house of prayer for all nations" signifies a radical openness and a breaking down of barriers that traditionally separated Jews from Gentiles in worship.

New Testament Reference:
The phrase is notably quoted by Jesus in the New Testament. In the Gospel of Mark 11:17, Jesus cleanses the temple and declares, "Is it not written: ‘My house will be called a house of prayer for all the nations’? But you have made it ‘a den of robbers.’” This event underscores Jesus' mission to restore the temple as a place of genuine worship and prayer, accessible to all people, and critiques the commercialization and corruption that had taken root.

Theological Significance:
The concept of a "house of prayer for all nations" is significant in biblical theology as it highlights God's universal plan of salvation and the inclusivity of His kingdom. It reflects the breaking down of ethnic and cultural barriers, emphasizing that worship and relationship with God are open to all who seek Him. This theme is consistent with the broader biblical narrative of God's desire for all nations to know Him, as seen in the Great Commission (Matthew 28:19-20) and the vision of a diverse multitude worshiping God in Revelation 7:9.

Historical and Cultural Context:
In the ancient Near Eastern context, temples were often seen as exclusive spaces for specific ethnic or religious groups. The Jewish temple in Jerusalem was no exception, with distinct areas designated for Jews and Gentiles. The prophetic vision in Isaiah and Jesus' actions in the temple challenge this exclusivity, pointing towards a future where all people can come together in worship.

Implications for Worship and Community:
The idea of a "house of prayer for all nations" has profound implications for contemporary worship and community life. It calls for inclusivity and hospitality within places of worship, encouraging communities to embrace diversity and welcome all individuals, regardless of their background. This vision challenges believers to create spaces where prayer and worship are central and accessible to everyone.

Related Concepts:
· Temple Cleansing: Jesus' cleansing of the temple is a direct action that reinforces the prophetic vision of a house of prayer for all nations.
· Inclusivity in Worship: The biblical call for inclusivity in worship is a recurring theme, seen in the early church's outreach to Gentiles and the breaking down of dividing walls (Ephesians 2:14).
· Universal Salvation: The notion that God's salvation is available to all people, transcending ethnic and cultural boundaries, is a core tenet of Christian theology.

Conclusion:
The phrase "A House of Prayer for All Nations" encapsulates a vision of inclusivity and universal access to God, challenging believers to reflect this openness in their worship practices and community life.