The following is from the Avnei Shoham
??-???? ?????? ????????? ????? ??????? ????????????:
In the 1st bracha of Shmoneh Esrei all the letters of the Alef Beis appear. This is what we refer to when we say the above passuk, ?????, and all the sounds (i.e. letters) which we emanate from our mouth, ??????? ???????????? will recite your praises.
Interestingly, there is one letter missing in the 1st bracha, that being the letter ?. Therefore, Chazal, in their wisdom, added the passuk ??-???? ?????? ????????? ????? ??????? ???????????? to the beginning of the Shmoneh Esrei, which contains the letter ? 3 times, in order to ensure all letters are said.
Only with this passuk can we truly claim that our mouths will praise Hashem will all his letters.
This fact shows us that this passuk is actually quite vital to our Amida.