Albert Barnes Commentary 1 Thessalonians 2:11

"as ye know how we [dealt with] each one of you, as a father with his own children, exhorting you, and encouraging [you], and testifying," — 1 Thessalonians 2:11 (ASV)

How we exhorted. That is, to a holy life.

And comforted. In the times of affliction.

And charged. Greek: testified. The word testify is used here in the sense of protesting, or making an earnest and solemn appeal. They came as witnesses from God to the truth of religion and to the importance of living in a holy manner. They did not originate the gospel themselves, or teach its duties and doctrines as their own. Instead, they came in the capacity of those who bore witness to what God had revealed and required, and they did this in the earnest and solemn manner that befitted such an office.

As a father doth his children. With an interest in your welfare, such as a father feels for his children, and with such a method as a father would use. It was not done in a harsh, dictatorial, and arbitrary manner, but in tenderness and love.