The messenger of Satan was a pharisee like Paul, who was sent from Jerusalem by Satan, and was a false apostle, who went behind Paul to hinder Paul in raising up Churches among the Gentiles, by teaching these gentiles they must become circumcised and keep the law of Moses, to be saved.
Apostle means "sent".
This false apostle, who was sent by Satan, just as Paul was sent by Jesus Christ as a true apostle, and carried the true Gospel, likewise the false apostle sent by Satan carried "another" gospel, which was designed to stop Paul's progress, by causing him to come back to those Churches and spend more time "undoing" the damage this false gospel had done.
Paul explains this in the previous chapter, 2 Corinthians 11.
12 But what I do, I will also continue to do, that I may cut off the opportunity from those who desire an opportunity to be regarded just as we are in the things of which they boast. 13 For such are false apostles, deceitful workers, transforming themselves into apostles of Christ. 14 And no wonder! For Satan himself transforms himself into an angel of light.15 Therefore it is no great thing if his ministers also transform themselves into ministers of righteousness, whose end will be according to their works. 2 Corinthians 11:12-15
This actually worked together for good, for Paul, since he was "hardwired" towards the law as a Pharisee of Pharisee's, Paul was forced to build with Christ, and Him crucified, rather than the wisdom God had given him, about the old testament, and the revelations about Christ and the Church found in those scriptures. Paul had fervently wanted to teach these things to his countrymen after the flesh, the Hebrews, since all this would make no since to the unlearned Gentiles. This worked out for good, since God had intended for Paul to rely on the Holy Spirit rather than his vast knowledge of the scriptures, so that...that your faith should not be in the wisdom of men but in the power of God.
JLB
Buffet - Strong's G2852 - kolaphizō
- to strike with the fist, give one a blow with the fist
- to maltreat, treat with violence and contumely
This buffeting came from other human beings.
Example:
19 Then Jews from Antioch and Iconium came there; and having persuaded the multitudes, they stoned Paul and dragged him out of the city, supposing him to be dead. 20 However, when the disciples gathered around him, he rose up and went into the city. And the next day he departed with Barnabas to Derbe. Acts 14:19-20
JLB