Q: How are the Haftarah and B’rit Hadashah portions selected, and are they the same pairing every year?
A: As mentioned in the question about the Torah cycle, the Haftarah was created essentially during the Babylonian captivity. The Jews were forbidden from reading and studying the Torah. They were not, however, forbidden from the rest of the Bible. The leaders of the day were so familiar with the Torah that they were able to, from memory, select a passage from the rest of the Bible (which was just the Old Testament at the time) that some how related to or reminded of the portion from the Torah that would have been read that Shabbat if they had been allowed.
For example, the Torah portion for Parshat Balak, which is June 26th, is Numbers 22:2-25:9. It encompasses the interaction between Balak, king of Moab, and Balaam, a prophet of the day. When the Jewish people were no longer able to read about this from the Torah, a passage from the prophet Micah was chosen, Micah 5:6-6:8. In Micah 6:5, the people are called upon to remember the events of Balak and Balaam. For that reason, it was selected to be read when the actual Torah portion could not.
There did come a time when the Jews were permitted once again to read and study the Torah. But rather than simply discard the passage from the prophets they had been reading and studying for years, they kept that, too. So each Shabbat, a portion is read from the Torah and the Haftarah, both of which are set every year. The Torah portion is inextricably linked to a Haftarah portion.
Not so with the B’rit Hadashah. Several different organizations have developed a reading cycle for the B’rit Hadashah. While the readings are sometimes different, the goal is the same. The readings should all connect, somehow. That is, the B’rit Hadashah portion should somehow connect with the Torah portion, Haftarah portion, or preferably, both. While sometimes the connections can be somewhat obscure, more often than not there is a prevailing theme that can be identified throughout the three readings. So for examples of a B’rit Hadashah cycle, you can check out Chosen People Ministries, who use the B’rit Hadashah readings from The Foundation for Leadership and Messianic Education (FLAME). Or, if you have a Complete Jewish Bible, at the end of each Torah portion, there are several different B’rit Hadashah portions listed.
But the bottom line is that the Torah portion and Haftarah portions are fixed, the B’rit Hadashah is not. Does this mean that a rabbi will never deviate from the appointed schedule? No. It just means that when it is done, it is a departure from what the rest of the community is doing. And it should be the exception, not the norm. For me, in the absence of a clear message from the Lord to change, I will stick with the given readings. I have been known to depart from the published B’rit Hadashah portion from time to time as the Spirit leads, but will keep with the Torah and Haftarah of tradition.