In the New Testament, the role of an apostle is foundational to the establishment and growth of the early Church. Apostles were chosen and sent by Jesus Christ to preach the Gospel, establish churches, and provide authoritative teaching. The signs of a true apostle are critical for distinguishing genuine apostolic authority from false claims. These signs are primarily derived from the teachings and writings of the Apostle Paul, who often defended his apostolic authority against detractors.

1. Divine Commissioning and Witness of the Resurrected Christ

A true apostle is directly commissioned by Jesus Christ and is a witness to His resurrection. This is evident in the calling of the original twelve apostles and Paul’s own experience. Paul emphasizes his encounter with the risen Christ as a validation of his apostleship: "Am I not an apostle? Have I not seen Jesus our Lord?" (1 Corinthians 9:1). This personal encounter with Christ is a foundational sign of true apostleship.

2. Signs, Wonders, and Miracles

The performance of signs, wonders, and miracles is a hallmark of apostolic ministry. These acts serve as divine confirmation of an apostle’s message and authority. Paul refers to these signs in his defense of his apostleship: "The true marks of an apostle—signs, wonders, and miracles—were performed among you with great perseverance" (2 Corinthians 12:12). Such miraculous works authenticate the apostle’s divine mission and message.

3. Foundational Role in the Church

Apostles hold a foundational role in the establishment of the Church. Ephesians 2:20 describes the Church as "built on the foundation of the apostles and prophets, with Christ Jesus Himself as the cornerstone" . This foundational role includes the establishment of doctrine, church governance, and the spread of the Gospel to new regions.

4. Suffering and Perseverance

True apostles often endure significant suffering and persecution for the sake of the Gospel. Paul’s own life exemplifies this, as he recounts his hardships in 2 Corinthians 11:23-28, detailing imprisonments, beatings, and other trials. Such perseverance in the face of adversity is a testament to the authenticity of their calling and commitment to Christ.

5. Holiness and Integrity

Apostles are expected to lead lives of holiness and integrity, serving as examples to the believers. Paul exhorts the Thessalonians to remember his conduct among them: "You are witnesses, and so is God, of how holy, righteous, and blameless our conduct was among you who believed" (1 Thessalonians 2:10). The moral character of an apostle is a crucial sign of their genuine calling.

6. Teaching and Doctrinal Soundness

Apostles are entrusted with the teaching of sound doctrine. They are responsible for preserving the truth of the Gospel and correcting false teachings. Paul instructs Timothy to "retain the standard of sound words" and to "guard the treasure entrusted to you" (2 Timothy 1:13-14). The ability to teach and uphold doctrinal purity is a key sign of a true apostle.

7. Spiritual Authority and Leadership

Apostles possess spiritual authority and leadership within the Church. This authority is exercised not through domination but through service and edification of the body of Christ. Paul’s letters often reflect his authoritative yet pastoral role, guiding and correcting the churches he established.

In summary, the signs of a true apostle encompass divine commissioning, miraculous works, foundational church roles, perseverance through suffering, personal holiness, doctrinal soundness, and spiritual authority. These characteristics collectively affirm the authenticity of an apostle’s calling and mission in the early Church.