Definition and Significance:
Altar dedication in the biblical context refers to the consecration and sanctification of an altar for worship and sacrifice to God. This act signifies the setting apart of a physical space for divine purposes, often accompanied by rituals, offerings, and prayers. The dedication of an altar is a profound expression of commitment to God and acknowledgment of His sovereignty.

Old Testament Instances:

1. Patriarchal Altars:
The practice of altar dedication can be traced back to the patriarchs. Noah built an altar to the LORD after the flood and offered burnt offerings (Genesis 8:20). Abraham, Isaac, and Jacob also erected altars as acts of worship and covenantal remembrance (Genesis 12:7-8; 26:25; 35:7).

2. Mosaic Covenant:
The dedication of the altar is prominently featured in the Mosaic Law. In Exodus 29, God instructs Moses on the consecration of the altar as part of the ordination of Aaron and his sons. The altar of burnt offering was anointed and sanctified, making it "most holy" (Exodus 29:37).

3. Solomon’s Temple:
One of the most significant altar dedications occurred during the dedication of Solomon's Temple. Solomon offered a prayer of dedication and numerous sacrifices, and the glory of the LORD filled the temple (1 Kings 8:22-64; 2 Chronicles 7:1-7). This event underscored the centrality of the altar in Israel's worship.

4. Post-Exilic Restoration:
After the Babylonian exile, the returning exiles rebuilt the altar under the leadership of Jeshua and Zerubbabel. They dedicated it and resumed the sacrificial system as prescribed in the Law of Moses (Ezra 3:2-6).

New Testament Context:

While the New Testament does not focus on physical altars in the same way as the Old Testament, the concept of dedication and consecration remains significant. Believers are called to present their bodies as living sacrifices, holy and pleasing to God (Romans 12:1). This spiritual act of dedication reflects the heart of altar dedication—setting apart oneself for God's service.

Theological Implications:

1. Holiness and Separation:
Altar dedication emphasizes the holiness required in approaching God. The act of consecration signifies a separation from the common and a devotion to the sacred.

2. Covenant Relationship:
The dedication of altars often accompanies covenantal events, symbolizing the relationship between God and His people. It serves as a physical reminder of God's promises and the people's commitment to obey His commands.

3. Worship and Sacrifice:
Altars are central to the worship practices of Israel, serving as the place where sacrifices are offered. The dedication of an altar is an acknowledgment of God's provision and a response of gratitude and obedience.

Practical Application:

In contemporary Christian practice, while physical altars are not a central focus, the principles of dedication and consecration remain vital. Believers are encouraged to dedicate their lives, homes, and places of worship to God, ensuring that all aspects of life are aligned with His will and purpose.