There is a common fantasy that the secret to our survival as a people has been rigidity. But at least as far as worship is concerned, nothing could be further from the truth. If we could be magically transported back 3000 years to biblical times, or even 2000 years to the time the Temple was standing in Jerusalem, the worship services would be hardly recognizable and barely tolerable (unless you like killing sheep, which hopefully you don’t).
A transformation took place at the time the Temple was destroyed in 70 CE. On the one hand, the entire elaborate priestly institution—cohanim, leviim, sacrifices, pilgrimages, tithes, etc.—collapsed. On the other hand, liturgical forces that had already been building as a compliment to, and a competitor to, the sacrificial system could come to the fore. Over the next several hundred years, and not without opposition, prayer became a substitute for sacrifice.
This was a remarkable and massive transformation. The Torah commands sacrifice. The rabbis, in their audacity, offered a substitute. The tension between them is reflected in the “Service”—Avodah—blessing, which begins the conclusion of all amidot. Here, the concepts of prayer and sacrifice are skillfully interwoven. “Find favor, Lord our G-d, in Your people Israel and in their prayer. And return the sacrificial service to the holy midst of your Temple home, and the burnt sacrifices and prayers of Israel accept in favor. And may the service of Israel Your people always be favorable.”
Note the pattern: prayer, sacrifice, sacrifice, prayer. And in the conclusion avodah—which generally refers specifically to sacrifice, as in the Avodah service on Yom Kippur—is here transformed into a more general reference to “service”—in whatever form it takes.
We come then to the conclusion of the blessing, “May our eyes behold your return to Zion in mercy. Blessed are You, Lord, Who restores His Divine Presence to Zion.” Note that it takes no stand on what kind of worship will then ensue. Will it be sacrifice? Or will our 2000 experience with prayer replace it? Or will it be something else, like philosophical contemplation (Maimonides hints at this)? The text is deliberately ambiguous.
Which carries a message of its own—don’t worry about the “right” way to worship G-d. Just worship G-d in a way that is favorable, and the rest will follow. With one caveat: this prayer repeatedly refers to the people of Israel. Prayer is meant to be collective, not private. That’s what the minyan is for.