John Calvin Commentary 2 Corinthians 1:5

"For as the sufferings of Christ abound unto us, even so our comfort also aboundeth through Christ." — 2 Corinthians 1:5 (ASV)

For as the sufferings of Christ abound — This statement may be explained in two ways: actively and passively. If you take it actively, the meaning will be this: “The more I am tried with various afflictions, the more resources I have for comforting others.” I am, however, more inclined to take it in a passive sense, meaning that God multiplied His consolations according to the measure of His tribulations. David also acknowledges that this was his experience:

According to the multitude of my anxieties within me, says he,
Your consolations have delighted my soul (Psalms 94:19).

In Paul’s words, however, there is a fuller statement of doctrine, for he calls the afflictions of the pious the sufferings of Christ, as he says elsewhere:

that he fills up in his body what is lacking in the
sufferings of Christ (Colossians 1:24).

The miseries and vexations of the present life, it is true, are common to good and bad alike. However, when they befall the wicked, they are signs of God’s curse, because they arise from sin, and nothing appears in them except the anger of God and participation with Adam, which inevitably depresses the mind.

Meanwhile, believers are conformed to Christ and bear about with them in their body His dying, that the life of Christ may one day be manifested in them (2 Corinthians 4:10).

I speak of the afflictions believers endure for the testimony of Christ, (Revelation 1:9), for although the Lord’s chastisements, with which He chastises their sins, are beneficial to them, they are, nevertheless, not participants, properly speaking, in Christ’s sufferings, except in those cases in which they suffer on His account, as we find in 1 Peter 4:13.

Paul’s meaning, then, is that God is always present with him in his tribulations, and that his weakness is sustained by the consolations of Christ, preventing him from being overwhelmed by calamities.