There is a halakhah of semikhas ge’ulah letefillah, that one must finish the last berakhah after Shema, that about the redemption, immediately before the Shemoneh Esrei, with no interruptions. The Mishnah Berurah even advises that in Shacharis the chazan should whisper the end of the berakhah to himself, so that the congregation would not be obligated to interrupt between their own birkhas Ge’ulah and Shemoneh Esrei by having to answer amein.
In Ma’ariv, we insert “Hashkiveinu“, a berakhah about peace, and outside of Israel most communities also say “Barukh Hashem leOlam“. These are generally justified because Hashkiveinu is also on the broader subject of redemption, and Barukh Hashem leOlam is a surrogate for Shemoneh Esrei. So the concepts of ge’ulah and tefillah are still juxtaposed. A full discussion is off topic, but even in the case of Ma’ariv, R’ JB Soloveitchik would limit his responses to the intervening Qaddish to just “Amein. Yehei Shemei rabba…” and the final “amein” since these interruptions are mandatory, whereas the other reponses to Qaddish are custom.
Why the need to so closely preface ge’ulah to tefillah?
Ga’al Yisrael speaks of past redemption. We point to the miracle at the Red Sea and other redemptions as a source of emunah, of belief in the existance and involvement of the A-lmighty. We establish the foundation that there is a G-d capable of aiding us and we know this because He has in the past. It is only with that concept that Hashem is Omnipotent and involved in human affairs that it is meaningful to engage in the praise, requests and thanks of tefillah, to expect His involvement in our own lives.That’s bitachon, the belief of Hashem’s actual involvement in the present and future, that He can be relied upon..