Definition and Significance
Being full of the Holy Spirit refers to a state in which a believer is deeply influenced, guided, and empowered by the Holy Spirit. This condition is characterized by a profound sense of God's presence, spiritual insight, and the ability to perform acts that align with God's will. It is a recurring theme in the New Testament, illustrating the transformative power of the Holy Spirit in the lives of believers.

Biblical Instances
The concept of being full of the Holy Spirit is prominently featured in the Book of Acts. One of the earliest examples is found in Acts 2:4, where the apostles, gathered on the day of Pentecost, "were all filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them." This event marks the birth of the Church and demonstrates the empowering presence of the Holy Spirit for the purpose of witness and ministry.

Another significant instance is seen in the life of Stephen, one of the first deacons of the early Church. Acts 6:5 describes Stephen as "a man full of faith and of the Holy Spirit." His fullness of the Spirit is further evidenced in Acts 7:55, where, even as he faced martyrdom, Stephen "looked up to heaven and saw the glory of God, and Jesus standing at the right hand of God."

The Apostle Paul also experienced being full of the Holy Spirit. In Acts 13:9, Paul, filled with the Holy Spirit, confronts Elymas the sorcerer, demonstrating the Spirit's power to overcome opposition to the Gospel.

Characteristics and Evidence
Being full of the Holy Spirit is often associated with certain characteristics and behaviors. These include boldness in proclaiming the Gospel (Acts 4:31), wisdom and discernment (Acts 6:3), and the ability to perform signs and wonders (Acts 2:43). The fruit of the Spirit, as outlined in Galatians 5:22-23, also serves as evidence of the Spirit's fullness in a believer's life, manifesting as love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control.

Theological Implications
Theologically, being full of the Holy Spirit underscores the intimate relationship between the believer and the Triune God. It highlights the role of the Holy Spirit as the active presence of God in the world, empowering believers to live out their faith in practical and transformative ways. This state is not a one-time event but a continual process of yielding to the Spirit's influence and guidance.

Practical Application
For believers, seeking to be full of the Holy Spirit involves a life of prayer, obedience, and surrender to God's will. Ephesians 5:18 exhorts believers to "be filled with the Spirit," indicating an ongoing, dynamic relationship with the Holy Spirit. This involves a conscious effort to live in accordance with God's Word and to be open to the Spirit's leading in all aspects of life.

Conclusion
The concept of being full of the Holy Spirit is central to the Christian experience, providing believers with the power and guidance necessary to live a life that honors God and advances His kingdom on earth. Through the Holy Spirit, believers are equipped to face challenges, serve others, and bear witness to the transformative power of the Gospel.