“John did not naturally possess the loveliness of character that his later experience revealed. By nature he had serious defects. He was not only proud, self-assertive, and ambitious for honor, but impetuous, and resentful under injury. He and his brother were called “ sons of thunder ” (Mark 3:17). Evil temper, the desire for revenge, the spirit of criticism, were all in the beloved disciple. But beneath all this the divine Teacher discerned the ardent, sincere, loving heart. Jesus rebuked this self-seeking, disappointed his ambitions, tested his faith. …
“The defects in John’s character came strongly to the front on several occasions during his personal association with the Saviour. At one time Christ sent messengers before Him into a village of the Samaritans, requesting the people to prepare refreshments for Him and His disciples. But when the Saviour approached the town, He appeared to be desirous of passing on toward Jerusalem. This aroused the envy of the Samaritans, and … they withheld the courtesies which they would have given to a common wayfarer. …
“… the coldness, jealousy, and disrespect shown to their Master filled them with surprise and indignation. James and John especially were aroused. … In their zeal they said, ‘Lord, wilt Thou that we command fire to come down from heaven, and consume them, even as Elias did?’ … They were surprised to see that Jesus was pained by their words, and still more surprised as His rebuke fell upon their ears … (Luke 9:54–56). …
“At another time during their early evangelistic labors, James and John met one who, while not an acknowledged follower of Christ, was casting out devils in His name. The disciples forbade the man to work and thought they were right in doing this. But when they laid the matter before Christ, He reproved them, saying, ‘Forbid him not: for there is no man which shall do a miracle in My name, that can lightly speak evil of Me’ (Mark 9:39). … James and John had thought that in checking this man they had in view the Lord’s honor; but they began to see that they were jealous for their own. They acknowledged their error and accepted the reproof.
“The lessons of Christ, setting forth meekness and humility and love as essential to growth in grace and a fitness for His work, were of the highest value to John. He treasured every lesson and constantly sought to bring his life into harmony with the divine pattern. John had begun to discern the glory of Christ—not the worldly pomp and power for which he had been taught to hope, but ‘the glory as of the Only Begotten of the Father, full of grace and truth’ (John 1:14).” The Acts of the Apostles, 540–544.
Until they were converted, they were surely sons of thunder.