Noah and Avraham
(ט) אֵלֶּה תּוֹלְדֹת נֹחַ נֹחַ אִישׁ צַדִּיק תָּמִים הָיָה בְּדֹרֹתָיו אֶת הָאֱלֹהִים הִתְהַלֶּךְ נֹחַ.
(9) These are the generations of Noah. Noah was in his generations a man righteous and sincere; Noah walked with God.
(א) וַיְהִי אַבְרָם בֶּן תִּשְׁעִים שָׁנָה וְתֵשַׁע שָׁנִים וַיֵּרָא יְהוָה אֶל אַבְרָם וַיֹּאמֶר אֵלָיו אֲנִי אֵל שַׁדַּי הִתְהַלֵּךְ לְפָנַי וֶהְיֵה תָמִים.
(1) And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him: ‘I am God Almighty; walk before Me, and be thou sincere.

There is an obvious question: The Torah calls Noah "sincere", and we have Hashem telling Avraham "be sincere". Evidently, Noah has a quality that Avraham does not? Therefore our Hakhamim deal with this textual problem in the following Midrash brought down by Rashi.

(ב) "בדורותיו" - (סנהדרין קט) יש מרבותינו דורשים אותו לשבח: כ"ש שאלו היה בדור צדיקים היה צדיק יותר. ויש שדורשים אותו לגנאי: לפי דורו היה צדיק, ואלו היה בדורו של אברהם לא היה נחשב לכלום.
(2) "In his generation..." - (Sanhedrin 109) Some of our rabbis interpret this as praise, meaning, all the more so, if he had been in a generation filled with righteous people, he would have been even more righteous. And there are those who interpret it as criticism, meaning, if he had been in Abraham's generation, he would not have been thought of as anything special.

Note: These two opinions on the character of Noah (one saying he would have been a better person in a righteous generation, and the other saying he would be regular) only disagree on the potential he might have had if he lived in a righteous generation. But they both agree that his righteousness can at best be described as mediocre.

The contrast between Noah and Avraham is further understood by their differing reactions to a similar situation. Noah and Avraham were both warned about the destruction of mankind by Hashem:

When Noah was told about the destruction of world in the following Pasuk :

(יג) וַיֹּאמֶר אֱלֹהִים לְנֹחַ קֵץ כָּל בָּשָׂר בָּא לְפָנַי כִּי מָלְאָה הָאָרֶץ חָמָס מִפְּנֵיהֶם וְהִנְנִי מַשְׁחִיתָם אֶת הָאָרֶץ. (יד) עֲשֵׂה לְךָ תֵּבַת עֲצֵי גֹפֶר קִנִּים תַּעֲשֶׂה אֶת הַתֵּבָה וְכָפַרְתָּ אֹתָהּ מִבַּיִת וּמִחוּץ בַּכֹּפֶר. (טו) וְזֶה אֲשֶׁר תַּעֲשֶׂה אֹתָהּ שְׁלֹשׁ מֵאוֹת אַמָּה אֹרֶךְ הַתֵּבָה חֲמִשִּׁים אַמָּה רָחְבָּהּ וּשְׁלֹשִׁים אַמָּה קוֹמָתָהּ. (טז) צֹהַר תַּעֲשֶׂה לַתֵּבָה וְאֶל אַמָּה תְּכַלֶנָּה מִלְמַעְלָה וּפֶתַח הַתֵּבָה בְּצִדָּהּ תָּשִׂים תַּחְתִּיִּם שְׁנִיִּם וּשְׁלִשִׁים תַּעֲשֶׂהָ. (יז) וַאֲנִי הִנְנִי מֵבִיא אֶת הַמַּבּוּל מַיִם עַל הָאָרֶץ לְשַׁחֵת כָּל בָּשָׂר אֲשֶׁר בּוֹ רוּחַ חַיִּים מִתַּחַת הַשָּׁמָיִם כֹּל אֲשֶׁר בָּאָרֶץ יִגְוָע. (יח) וַהֲקִמֹתִי אֶת בְּרִיתִי אִתָּךְ וּבָאתָ אֶל הַתֵּבָה אַתָּה וּבָנֶיךָ וְאִשְׁתְּךָ וּנְשֵׁי בָנֶיךָ אִתָּךְ. (יט) וּמִכָּל הָחַי מִכָּל בָּשָׂר שְׁנַיִם מִכֹּל תָּבִיא אֶל הַתֵּבָה לְהַחֲיֹת אִתָּךְ זָכָר וּנְקֵבָה יִהְיוּ. (כ) מֵהָעוֹף לְמִינֵהוּ וּמִן הַבְּהֵמָה לְמִינָהּ מִכֹּל רֶמֶשׂ הָאֲדָמָה לְמִינֵהוּ שְׁנַיִם מִכֹּל יָבֹאוּ אֵלֶיךָ לְהַחֲיוֹת. (כא) וְאַתָּה קַח לְךָ מִכָּל מַאֲכָל אֲשֶׁר יֵאָכֵל וְאָסַפְתָּ אֵלֶיךָ וְהָיָה לְךָ וְלָהֶם לְאָכְלָה. (כב) וַיַּעַשׂ נֹחַ כְּכֹל אֲשֶׁר צִוָּה אֹתוֹ אֱלֹהִים כֵּן עָשָׂה.
(13) And God said unto Noah: ‘The end of all flesh is come before Me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth. (14) Make thee an ark of gopher wood; with rooms shalt thou make the ark, and shalt pitch it within and without with pitch. (15) And this is how thou shalt make it: the length of the ark three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits. (16) A light shalt thou make to the ark, and to a cubit shalt thou finish it upward; and the door of the ark shalt thou set in the side thereof; with lower, second, and third stories shalt thou make it. (17) And I, behold, I do bring the flood of waters upon the earth, to destroy all flesh, wherein is the breath of life, from under heaven; every thing that is in the earth shall perish. (18) But I will establish My covenant with thee; and thou shalt come into the ark, thou, and thy sons, and thy wife, and thy sons’wives with thee. (19) And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female. (20) Of the fowl after their kind, and of the cattle after their kind, of every creeping thing of the ground after its kind, two of every sort shall come unto thee, to keep them alive. (21) And take thou unto thee of all food that is eaten, and gather it to thee; and it shall be for food for thee, and for them.’ (22) Thus did Noah; according to all that God commanded him, so did he.
Noah's reaction to the destruction of mankind? Silence. Noah did not react, he heard what Hashem had to say and he did not try and protest. Noah was a good person, but he was satisfied with his own salvation.
Avraham on the other hand reacted a little differently:

(כג) וַיִּגַּשׁ אַבְרָהָם וַיֹּאמַר הַאַף תִּסְפֶּה צַדִּיק עִם רָשָׁע.
(23) And Abraham drew near, and said: ‘Will You indeed sweep away the righteous with the wicked?
Immediately after Hashem informed him of the destruction of Sodom, Avraham sprang into action, trying to convince Hashem not to utterly destroy all of Sodom.

We can also reanalyze the first 2 Pesukim that we brought down;
(ט) אֵלֶּה תּוֹלְדֹת נֹחַ נֹחַ אִישׁ צַדִּיק תָּמִים הָיָה בְּדֹרֹתָיו אֶת הָאֱלֹהִים הִתְהַלֶּךְ נֹחַ.
(9) These are the generations of Noah. Noah was in his generations a man righteous and sincere; Noah walked with God.
This Passuk shows that Hashem wanted Noah to "Walk with him", side by side. This shows that Noah showed that he wanted to remove himself from the corruption of the generation- but he was not able to. Even so, since he showed that initial desire, Hashem came to his side and "walked with him"- helped him survive.

On the other hand, in regards to Avraham the Passuk uses a different language:


(א) וַיְהִי אַבְרָם בֶּן תִּשְׁעִים שָׁנָה וְתֵשַׁע שָׁנִים וַיֵּרָא יְהוָה אֶל אַבְרָם וַיֹּאמֶר אֵלָיו אֲנִי אֵל שַׁדַּי הִתְהַלֵּךְ לְפָנַי וֶהְיֵה תָמִים.
(1) And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him: ‘I am God Almighty; walk before Me, and be thou sincere.
The Passuk says that Avraham "walked in front of Hashem". As opposed to Noah, Avraham did not only show the desire to improve himself as opposed to his generation, but he also had the ability to. His "walking in front of God" is a figurative way of saying that he heralded in the age of monotheism.

Noah and Avraham were two very important men in the history of mankind, who were charged with two very different missions. The mission of Noah was the mission of survival. The world was at a cross roads that needed to be fixed, and Noah stepped up the the plate and ensured the survival and continuation of mankind. In that way he "walked with god" and kept the status quo alive. He paved the way for a person like Avraham to emerge armed with the mission of spreading God's word, and "walk in front of Hashem"