"Now I rejoice in my sufferings for your sake... filling up what is lacking in Christ's afflictions, for the sake of His body, that is, the church" - Colossians 1:24
It is considered a mark of maturity to endure the company of the unwanted, to abide the annoying, and bear the unbearable. And so it is, but this is not yet Christian maturity. A Christian is not merely to suffer another, but for another. This is love.
And love's call has an echo. It is suffering. "Christ suffered for us, leaving an example, [for us] to follow in His footsteps."
Suffering is but love's sweat. But unlike in physical exercise, where we expect to perspire, breaking a sweat often breaks off our goodwill. It's unpleasant and it takes us by surprise.
To suffer for another is, in negative terms, to incur the various costs of being virtuous. Put positively, it is a capital investment in another's life: to help raise a New Adam or a New Eve within them. Yet more, "if we suffer with [Jesus]... we will also be glorified with Him."
If we can, we're to rejoice "in so far as we share in Christ's sufferings." Truly, this is perfection to heaven, and psychosis to the world. Because who likes suffering? Our backs seem broad enough for but one cross. Indeed, gladly do we give, warmly do we speak, and supportively do we pray - not to share a sister's burden, but to subtly avoid it. Let Jesus do the "heavy" lifting.
And yet, Paul writes, "I rejoice in suffering, filling up what is lacking in Christ's afflictions." What could be lacking?
Perhaps, it is not Christ's afflictions that are lacking, but Christs'. Every Christian is to be like Christ to his neighbor: to love as loved, give as given, forgive as forgiven, and if need be, to suffer as suffered for. There is work to be done, and unglamorous glories to be won. It is unpleasant, maybe painful - but rest assured, "having suffered [only] a little while, God will Himself restore, confirm, strengthen and establish you."