What are the stigmata in Galatians 6:17?
From now on, let no one cause me trouble, for I bear on my body the marks [στίγματα] of Jesus.
Paul possibly was referring to scars received in different episodes of physical abuse during his Christian missionary activity.
2 Corinthians 11:23-27 (NASB)
23 Are they servants of Christ?—I speak as if insane—I more so; in
[a]far more labors, in [b]far more imprisonments, [c]beaten times
without number, often in danger of death. 24 Five times I received
from the Jews thirty-nine lashes. 25 Three times I was beaten with
rods, once I was stoned, three times I was shipwrecked, a night and a
day I have spent in the deep.
26 I have been on frequent journeys, in dangers from rivers, dangers from robbers, dangers from my countrymen, dangers from the Gentiles, dangers in the city, dangers in the wilderness, dangers on the sea, dangers among false brethren; 27 I have been in labor and hardship, [d]through many sleepless nights, in hunger and thirst, often without food, in cold and [e]exposure.
Perhaps also Paul meant that his way of life identified him as a follower of Christ.