After introducing G-d as the Creator, and then the Revealer, the last blessing after the Shema goes on to talk about G-d the Redeemer. There is, though, one fundamental difference between the first two of these blessings and the third one. Creation has happened—we’re here. Revelation has happened—we have the Torah. Redemption….well, not so much. Sure, we were redeemed from Egypt, and that means that no matter what we might face in the future—and we have faced a lot in our future—we know with certainty that redemption has happened, and will happen again.
But when? As the years of exile accumulated, as horror after horror were experienced, the contrast between the glory of the redemptive promise and the reality of the unredeemed world had become increasingly painful. And this was accentuated by the contrast between the abject condition of the Jewish people and the declaration, in the Shema itself, that “the Lord is our G-d”. How could it be that G-d’s very own people were living in exile? This was a situation that was crying out for rectification.
Hence the rabbis declared that the blessing of redemption should always be inseparable from the Amidah, the prayer in our liturgy. This is especially the case with the weekday Amidah, which contains in its central portion a full scale proto-Zionist programmatic outline of the glorious return to Jerusalem. But the same principle holds for our Shabbat prayers.
This serves to explain a common custom: when the shaliach tzibbur concludes the blessing of redemption with the words “ga’al yisrael”—“redeemer of Israel”—he or she will often lower their voice to the point where the last words become inaudible. That way, no one says “Amen,” which would cause the separation between the prayers that are meant to be inseparable.
If the custom of the shaliach tzibbur is not to lower their voice, then one can either say ga’al yisrael with them—and then you wouldn’t say amen, because you never say amen to your own blessing; or else one could begin the Amidah just before the shaliach tzibbur finishes ga’al yisrael—and you wouldn’t interrupt your Amidah to say amen to a blessing.
The bottom line is this: we should be dreaming about redemption every day, (at least) three times a day. Why? The story is told of Napoleon, who heard crying from a synagogue. When it was explained to him that it was tisha b’av, the anniversary of the destruction of the Temple, he said, “A people who can remember their land after nearly 2,000 years is sure to return to it.”