ליקוטי מוהר׳ן חלק א׳ קנה
כִּי עִקַּר הָעַצְבוּת וְהָעַצְלוּת, הוּא מֵחֲמַת חֶסְרוֹן אֱמוּנָה כְּמוֹ לְמָשָׁל, כְּשֶׁמַּנִּיחִין חִטָּה בְּאֶרֶץ טוֹבָה אֲזַי הוּא גָּדֵל וְצוֹמֵחַ יָפֶה, וְאֵינוֹ מַזִּיק לוֹ שׁוּם רוּחַ וְלא זִיקִים וּרְעָמִים וְזֶה מֵחֲמַת שֶׁיֵּשׁ כּחַ הַצּוֹמֵחַ וְכחַ הַגּוֹדֵל עַל כֵּן אֵינוֹ מַזִּיק לוֹ שׁוּם דָּבָר אֲבָל כְּשֶׁנּוֹתְנִין הַחִטָּה בְּאֶרֶץ שֶׁאֵינָהּ טוֹבָה לִזְרִיעָה אֲזַי הוּא נִרְקָב בָּאָרֶץ מֵחֲמַת שֶׁאֵין לוֹ כּחַ הַצּוֹמֵחַ וְכחַ הַגּוֹדֵל וֶ אֱמוּנָה הִיא בְּחִינַת כּחַ הַגּוֹדֵל וְכחַ הַצּוֹמֵחַ כְּמוֹ שֶׁכָּתוּב (אֶסְתֵּר ב) : "וַיְהִי אוֹמֵן אֶת הֲדַסָּה" לְשׁוֹן גִּדּוּל וּכְמוֹ שֶׁאָמְרוּ רַבּוֹתֵינוּ, זִכְרוֹנָם לִבְרָכָה (שַׁבָּת ל"א) : אֱמוּנָה זֶה סֵדֶר זְרָעִים
Likutei Maharan 1:155
For the root of sadness and laziness is because of a lack of faith, for example, when placing wheat in good ground, then it grows and sprouts beautifully, and no wind, nor bolts, nor thunderstorms harm it, and this is because there is the power of the sprouting and the power of the growing, therefore it is not damaged at all, but when placing wheat in a ground that is not good for planting, then it rots in the ground, because it does not have the power of the sprouting or growing. And faith is in the category of the power of the sprouter and grower, as it is written, "And he brought up Hadassah" (Esther 2:7) its language is one of growth, and just like our sages of blessed memory said, "Faith is (refers to) the order of seeds [one of the six orders of the Mishnah]" (BT Shabbat 31a).
ליקוטי מוהר׳ן חלק א׳ צא
כִּי יֵשׁ כַּמָּה מִינֵי אֱמוּנָה, יֵשׁ אֱמוּנָה שֶׁהוּא רַק בַּלֵּב וְהָעִקָּר שֶׁ צָּרִיך לִהְיוֹת לָאָדָם אֱמוּנָה כָּל כָּך עַד שֶׁיִּתְפַּשֵּׁט בְּכָל הָאֵיבָרִים כְּמוֹ שֶׁמּוּבָא בְּכִתְבֵי הָאֲרִ"י שֶׁצָּרִיך לְהַגְבִּיהַּ יָדָיו בִּשְׁעַת נְטִילָה נֶגֶד הָראשׁ, כְּדֵי לְקַבֵּל הַקְּדֻשָּׁה נִמְצָא שֶׁצָּרִיך לָזֶה אֱמוּנָה בְּהַיָּדַיִם לְהַאֲמִין שֶׁמֵּחֲמַת שֶׁמַּגְבִּיהַּ יָדָיו כְּנֶגֶד הָראשׁ, מְקַבֵּל הַקְּדֻשָּׁה
כִּי בְּלא אֱמוּנָה אֵינוֹ כְּלוּם, כְּמוֹ שֶׁכָּתוּב (תְּהִלִּים קי"ט) : "כָּל מִצְוֹתֶיך אֱמוּנָה" וּ כְשֶׁיֵּשׁ לוֹ אֱמוּנָה כָּזוֹ, בָּא מִן הָאֱמוּנָה אֶל הַשֵּׂכֶל וְכָל מַה שֶּׁמַּחֲזִיק אֶת עַצְמוֹ בֶּאֱמוּנָה, בָּא אֶל שֵׂכֶל יוֹתֵר כִּי הַדָּבָר שֶׁהָיָה צָרִיך מִתְּחִלָּה לְהַאֲמִין עַכְשָׁו כְּשֶׁבָּא אֶל אֱמוּנָה יוֹתֵר גְּדוֹלָה, מֵבִין הַדָּבָר הָרִאשׁוֹן בַּשֵּׂכֶל
וְזֶה שֶׁכָּתוּב בְּמשֶׁה וַיְהִי יָדָיו אֱמוּנָה שֶׁהָיָה לוֹ אֱמוּנָה כָּל כָּך גְּדוֹלָה עַד שֶׁנִּתְפַּשֵּׁט בְּכָל הָאֵיבָרִים שֶׁאֲפִלּוּ בְּיָדָיו הָיָה הָאֱמוּנָה כָּל כָּך גְּדוֹלָה עַד בּא הַשָּׁמֶשׁ, הַיְנוּ לְהַשֵּׂכֶל שֶׁל הַדָּבָר וְשֶׁמֶשׁ הוּא בְּחִינַת חָכְמָה
Likutei Maharan 1:91
There are various kinds of faith. There is faith that is only in the heart. But a person must have so much faith that it spreads to all his limbs. Thus the Kabbalistic writings mention that when washing one's hands to eat bread, one should raise them towards the head in order to receive holisness. Your faith must extend into your hands in order to believe that by raising them towards your head you receive holiness. Without faith, it is a meaningless gesture, for "All your commandments are faith" (Ps. 119:86).
If you are strong in your faith, you will evenutally come to understand what you believe in. The stronger your faith, the greater your understanding will become. At the outset you have no option but to have faith, because you cannot understand the matter, but through faith you will come to understand it.
[There will then be new, more exalted levels that will still be hidden from you and beyond your ability to understand. Here again you will have to make the effort to believe. You must always start with faith regarding the levels that are as yet hidden from you, but eventually you will understand them as well. This is an ongoing process. Your faith must be so strong that it spreads to every one of your limbs. This faith will bring you to true wisdom.] [This section is missing from at least one Hebrew version.]
Martin Buber, Tales of the Hasidim, What Does It Matter to You?
A hasid came to the rabbi of Kotzk. “Rabbi,” he complained, “I keep brooding and brooding, and don’t seem to be able to stop.” “What do you brood about?” asked the rabbi. “I keep brooding about whether there really is a judgment and a judge.” “What does it matter to you!” “Rabbi! If there is no judgment and no judge, then what does all creation mean!” “What does that matter to you!” “Rabbi! If there is no judgment and no judge, then what do the words of the Torah mean!” “What does that matter to you?” “Rabbi! ‘What does it matter to me?’ What does the rabbi think? What else could matter to me?” “Well, if it matters to you as much as all that,” said the rabbi of Kotzk, “then you are a good Jew after all—and it is quite all right for a good Jew to brood: nothing can go wrong with him.”
אֱמוּנָה
א. צָרִיךְ לְהַאֲמִין בְּהַשֵׁם יִתְבָּרַךְ בְּדֶרֶךְ אֱמוּנָה וְלֹא בְּדֶרֶךְ מוֹפֵת.
ב. עַל־יְדֵי עֲנָוָה תִּזְכֶּה לֶאֱמוּנָה.
ז. מִי שֶׁאֵינוֹ מֵכִין אֶת לִבּוֹ, אֵינוֹ יָכוֹל לָבוֹא לֶאֱמוּנָה.
ח. מִי שֶׁנֶּאֱבַד לוֹ אֵיזֶהוּ דָּבָר, בְּיָדוּעַ שֶׁנָּפַל מֵאֱמוּנָתוֹ.
Sefer Ha'middot, Faith Chapter 1
1. One must believe in God through faith and not through magic/proof.
2. Through humility you will come to faith.
8. A person who does not prepare his/her heart cannot come to faith.
9. (S)he who lost something, it is known that (s)he fell from his/her faith.