The Politics of Religion
The Herodians were one of the Jewish parties of Jerusalem and Judea during the human lifetime of Jesus Christ, the others being the Pharisees, Sadducees, Zealots and Essenes. Unlike the others however, the Herodians were primarily a political group, rather than religious - as their name implies, the Herodians were supporters of The Herods, and rule from Rome (see Ancient Empires - Rome). While the Pharisees and Sadduccees opposed Jesus Christ because they viewed Him as a competitor for religious leadership of the people, the collaborationist Herodians opposed the Messiah because they viewed His growing popularity as a political threat to their Roman masters.
"Render to Caesar the things that are Caesar's and to God the things that are God's"
The Herodians joined with the Pharisees to oppose Jesus Christ, even after witnessing His miracles:
"Again He entered the Synagogue, and a man was there who had a withered hand. And they watched Him, to see whether He would heal him on the Sabbath, so that they might accuse Him. And He said to the man who had the withered hand, "Come here."
"And He said to them, "Is it lawful on the Sabbath to do good or to do harm, to save life or to kill?" But they were silent."
"And He looked around at them with anger, grieved at their hardness of heart, and said to the man, "Stretch out your hand." He stretched it out, and his hand was restored. The Pharisees went out, and immediately held counsel with the Herodians against Him, how to destroy Him."
"Jesus withdrew with His disciples to the sea, and a great multitude from Galilee followed; also from Judea and Jerusalem and Idumea and from beyond the Jordan and from about Tyre and Sidon a great multitude, hearing all that He did, came to Him." (Mark 3:1-8 RSV)
Jesus' famous "Render to Caesar the things that are Caesar's, and to God the things that are God's" was in response to an attempted set-up by the Herodians and Pharisees:
"And they sent to Him some of the Pharisees and some of the Herodians, to entrap Him in his talk. And they came and said to Him, "Teacher, we know that You are true, and care for no man; for You do not regard the position of men, but truly teach The Way of God. Is it lawful to pay taxes to Caesar, or not? Should we pay them, or should we not?"
"But knowing their hypocrisy, He said to them, "Why put Me to the test? Bring me a coin, and let Me look at it." And they brought one. And He said to them, "Whose likeness and inscription is this?"
"They said to Him, "Caesar's."
"Jesus said to them, "Render to Caesar the things that are Caesar's, and to God the things that are God's."
"And they were amazed at Him." (Mark 12:13-17 RSV)
Fact Finder: As its name plainly says, how was the Church of Rome (in contrast to the Church of God) a political creation?
See The Politics Of The Papacy