While reading for the New Testament Challenge I was stopped in my reading when I read again the God's words to Ananias, “Go! This man [Paul] is my chosen instrument to carry my name before the Gentiles and their kings and before the people of Israel. I will show him how much he must suffer for my name” (Acts 9:15-16 ( NIV )).
Suffering? I thought he was called to serve? Turns out that Paul talks about service in terms of suffering and suffering in terms of service almost as much as he talks about the division of the Spirit and the flesh, except there are three distinct types of "suffering."
Persecution is suffering all believers endure. Some more benign, as in the West where Christians are treated as slightly demented relatives, and some much more severe as in North Korea where conversion is followed by death. In 1 Cor 4:12 Paul makes it clear that persecution is to be "endured" which leads me to pray for strong knees for prayer in my old age.
Tribulation is a more active attack from spiritual forces and could also be taken as "temptations" especially when they come from poor choices. We bring on tribulation by choosing to be with a certain crowd and then refusing participate in their chosen activities. Parents of school age children face tribulation in California as their children are taught tenants not consistent with the faith - but any rebuttal leads to prejudice shown to their children.
Suffering is more generic and could refer to "walking miles to do ministry" or "facing firing for not lying to a customer."
Jesus was calling Paul to suffer in all three categories - I invite you to send me examples of each.