Definition and Nature
An "Angel from Heaven" refers to a celestial being created by God, serving as His messenger and executing His will. Angels are spiritual entities that exist in the heavenly realm, distinct from human beings, and are often depicted as possessing great power and holiness. They are frequently mentioned throughout the Bible, fulfilling various roles and responsibilities as directed by God.

Biblical References
The Bible provides numerous accounts of angels appearing to individuals, delivering messages, and performing divine tasks. In the Old Testament, angels are often seen as God's messengers and warriors. For instance, in Genesis 28:12, Jacob dreams of a ladder reaching to heaven with angels ascending and descending on it, symbolizing the connection between God and humanity.

In the New Testament, angels play a significant role in the life and ministry of Jesus Christ. The angel Gabriel announces the birth of John the Baptist to Zechariah (Luke 1:11-20) and the birth of Jesus to Mary (Luke 1:26-38). At Jesus' resurrection, an angel rolls away the stone from the tomb and announces His resurrection to the women (Matthew 28:2-7).

Characteristics and Functions
Angels are described as mighty and powerful beings who serve God and carry out His commands. Psalm 103:20 states, "Bless the LORD, all His angels mighty in strength, who carry out His word, who hearken to the voice of His command." They are often depicted as worshiping God continually, as seen in Isaiah 6:2-3, where the seraphim proclaim, "Holy, holy, holy is the LORD of Hosts; His glory fills the whole earth."

Angels also serve as protectors and guides for believers. In Psalm 91:11, it is written, "For He will command His angels concerning you to guard you in all your ways." This protective role is further illustrated in the account of Daniel in the lions' den, where an angel shuts the mouths of the lions to protect Daniel (Daniel 6:22).

Warnings and Discernment
The Bible also warns against false angels or deceptive spirits. In Galatians 1:8, Paul cautions, "But even if we or an angel from heaven should preach a gospel contrary to the one we preached to you, let him be under a curse!" This highlights the importance of discernment and adherence to the true Gospel message.

Angelic Hierarchy and Orders
Scripture suggests a hierarchy among angels, with different orders and ranks. The archangel Michael is mentioned as a chief prince and warrior angel in Daniel 10:13 and Jude 1:9. The cherubim and seraphim are other orders of angels, each with specific roles and appearances, as described in Ezekiel 10 and Isaiah 6.

Role in Eschatology
In eschatological events, angels are depicted as active participants in God's final judgment and the establishment of His kingdom. Revelation 7:1-3 describes angels holding back the four winds of the earth, and Revelation 20:1-3 speaks of an angel binding Satan for a thousand years.

Conclusion
While angels are powerful and significant in the biblical narrative, they are ultimately servants of God, pointing to His glory and majesty. Believers are encouraged to recognize their role in God's divine plan while maintaining a focus on worshiping God alone.