Paul was in prison when he wrote that to the Colossians. His reference to “rejoicing in the sufferings” is most likely related to Christ’s words that they would suffer and endure afflictions for spreading His gospel. So Paul here is “rejoicing” because he felt it an honor to suffer for Christ and his body the church. Paul is also saying that his suffering doesn’t rise to the level of Christ’s suffering but is willing to go through or “be filled” with the same suffering as Christ if need be. Peter also referenced this.
1 Peter 3:14 But and if ye should suffer for righteousness' sake, blessed are ye: and fear not their fear, neither be troubled;
The apostles counted it a blessing to suffer for Christ and His body the church. Paul is saying that he is simply being filled with more of the same suffering Christ endured and like Peter believes he will be more blessed.
I understand the apostles’ joy at tribulation. And I understand that in itself is something God provides.
You said, “Paul is also saying that his suffering doesn’t rise to the level of Christ’s suffering but is willing to go through or “be filled” with the same suffering as Christ if need be.” Would you take the time to explain how you come to that conclusion from the construct of Paul’s sentence? I’m not a Greek scholar, but I don’t usually have trouble following Paul’s writings.
Your interpretation fits better with other scripture than what I’ve gotten from that sentence. I just need to understand how you derive that from the sentence.
Thank you for your patience.