(ט) אַתֶּם נִצָּבִים הַיּוֹם כֻּלְּכֶם לִפְנֵי יְהוָה אֱלֹהֵיכֶם רָאשֵׁיכֶם שִׁבְטֵיכֶם זִקְנֵיכֶם וְשֹׁטְרֵיכֶם כֹּל אִישׁ יִשְׂרָאֵל.
(9) Ye are standing this day all of you before the LORD your God: your heads, your tribes, your elders, and your officers, even all the men of Israel,
(א) וַיֵּלֶךְ מֹשֶׁה וַיְדַבֵּר אֶת הַדְּבָרִים הָאֵלֶּה אֶל כָּל יִשְׂרָאֵל.
(1) And Moses went and spoke these words unto all Israel.
An analysis of the names of these two parshiot shows that they have opposite meanings. The word nitzavim means “standing,” while vayeilech means “going.” Furthermore, nitzavim has the connotation not only of standing still, but “standing firm.” The root of the word, nitzav, is different from the word omed. The latter word is used to indicate that a person is standing, but that he could move at any second. Nitzav, however, has the connotation of standing rooted firmly to a spot; it’s much more solid than the word omed.
(ז) וְרַגְלֵיהֶם רֶגֶל יְשָׁרָה וְכַף רַגְלֵיהֶם כְּכַף רֶגֶל עֵגֶל וְנֹצְצִים כְּעֵין נְחֹשֶׁת קָלָל.
(7) And their feet were straight feet; and the sole of their feet was like the sole of a calf’s foot; and they sparkled like the colour of burnished brass.
We're can often find ourselves even more stuck than angels. Whereas we can be נצבים - angles are called עומדים.
(ז) כֹּה אָמַר יְהוָה צְבָאוֹת אִם בִּדְרָכַי תֵּלֵךְ וְאִם אֶת מִשְׁמַרְתִּי תִשְׁמֹר וְגַם אַתָּה תָּדִין אֶת בֵּיתִי וְגַם תִּשְׁמֹר אֶת חֲצֵרָי וְנָתַתִּי לְךָ מַהְלְכִים בֵּין הָעֹמְדִים הָאֵלֶּה.
(7) ’Thus saith the LORD of hosts: If thou wilt walk in My ways, and if thou wilt keep My charge, and wilt also judge My house, and wilt also keep My courts, then I will give thee free access among these that stand by.
“Human beings differ from angels in their ability to change, to grow and improve. Angels cannot change; they remain the same from the moment they come into existence until they expire. For this reason, the prophets generally describe angels as "Omedim," "standing." Angels stand in only one place, unable to advance or progress forward. Human beings, by contrast, are often referred to as "Holechim," "walking," referring to their capacity to progress, to move forward, to grow, to work on their characters and become better. If a person remains stagnant and complacent, if he has no interest in improving himself and advancing to the next level in religious observance and character refinement, then he has negated his most basic human quality.” (http://www.dailyhalacha.com/)
The Talmud states explicitly: “makom she-ba’alei teshuvah omdim tzadikkim gemurim einam yecholim la’amod, in a place where penitents are standing, the purely righteous are unable to stand” (Brachot, 34b). Why? Perhaps because they are just standing there and not doing the moving necessary for true תשובה.