"John 17:21 (KJV) - That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me."

This powerful verse from the book of John encapsulates the message that Jesus was trying to convey to his disciples before his crucifixion. It is a plea for unity among his followers, echoing the same sentiment found throughout his teachings and throughout the Bible as a whole. This verse is part of a larger prayer that Jesus delivers to God on behalf of his disciples, in which he petitions for their spiritual welfare as they carry on his mission in the world.

The theme of unity is central to this verse and the message it conveys. Jesus is praying for the oneness of his followers, just as he and the Father are one. This unity is not just about harmony or agreement among his followers, but a deep, spiritual oneness that mimics the relationship between Jesus and the Father. It is a unity that transcends individual differences and creates a bond that is rooted in the divine. This oneness is essential for the success of Jesus' mission, as it is through the unity of his followers that the world will come to believe in his message and his divinity.

The context of this verse is also important in understanding its significance. Jesus is speaking to his disciples at the Last Supper, just before he is to be betrayed and crucified. He knows that he will soon be leaving them, and he is deeply concerned for their well-being in his absence. This prayer is not only a request for unity, but also an expression of his love and care for his followers. It is a testament to the deep bond that Jesus shares with his disciples and his desire for their continued spiritual growth and strength.

The symbolism in this verse is rich and layered. The image of Jesus and the Father being one is a profound representation of the unity within the Godhead. It speaks to the mysterious and holy relationship between God the Father and God the Son, and the divine nature of their unity. This image serves as a model for the oneness that Jesus desires for his followers, a unity that is reflective of the divine love and harmony that exists within the Godhead.

Furthermore, the symbolism of unity as a means of bringing the world to belief is crucial in understanding the broader implications of this verse. Jesus is not only concerned with the unity of his immediate followers, but also with the impact that this unity will have on the world. The unity of his followers is meant to serve as a witness to the power and truth of his message, drawing others to faith and belief in him. It is a powerful symbol of the transformative nature of the Gospel and the potential for it to bring about a profound change in the world.

In conclusion, John 17:21 is a poignant and deeply meaningful verse that captures the heart of Jesus' message to his disciples. It is a prayer for unity that reflects the divine oneness within the Godhead, and it serves as a powerful symbol of the transformative potential of faith and belief. Its themes of unity, love, and witness are as relevant today as they were in the time of Jesus, and it continues to inspire and challenge believers to strive for the same deep, spiritual oneness that Jesus prayed for his followers.