[adapted by Rabbi Shmuel Jablon from Rav Aviner's three-volume commentary on the siddur "Tefilat Amecha"]
The Shemone Esrei, also known as the Amida, is the central part of our davening. Everything up to this point has been to prepare to speak directly with Hashem. Though there are many requests that we make, requests are not the essence of Tefilla. If it were, that would be service of ourselves, rather than of Hashem. Rather, the essence of Tefilla is "Devekut" – close connection to Hashem. When we daven, our souls reach for Hashem to connect with Him.
There are three ways that we have a close connection to Hashem. We have this close connection with our minds, which we achieve through learning Torah. We have this with our deeds, which we achieve through doing mitzvot. And we do this with our words, which we achieve with our Tefillot. Our words express our desire to get closer to Hashem. Sometimes it is hard to light this fire - to have our Tefillot truly express our soul’s great desires. But we cannot give up. As we keep davening, and understanding our davening, we find that there are indeed times that we have this deep, emotional connection to Hashem through our speaking directly with Him. These feelings of "Devekut" can come upon us and we can feel an incredible closeness to Hashem. But we have to give ourselves the opportunity, through regular and proper davening. It’s true that Hashem knows what we need before we ask Him. But He wants us to ask Him. He wants us to have this deep connection with Him, just as He has this deep connection to all of us. And so we come before Hashem during the Shemoneh Esrei. We give him praises and thanks. But we also make requests - not just for our needs but for the needs of all Klal Yisrael.
Right before the Shemoneh Esrei we say a verse: "Hashem open up my lips and my mouth to say your praises." Even though we are not allowed to have a break between the blessing of Ga’al Yisrael and the Amida, this is not considered a break. It is considered to be an extension of Ga’al Yisrael. We say it not because we have any physical problems talking. We say it because we need permission to come before Hashem and speak with Him. When you think about it, it is astounding that we would have the courage to speak to Hashem, the Ruler of the Universe. So we ask His permission to allow us to speak. We do this using the expression "Hashem". We are saying that we recognize that He is our personal ruler. We are again saying we believe in Him and will honor His commandments. Once we do this, we are then ready to come before Hashem with our praises, requests and thanks in the Shemoneh Esrei itself.