אלא פרשת ציצית מפני מה קבעוה א"ר יהודה בר חביבא מפני שיש בה חמשה דברים מצות ציצית יציאת מצרים עול מצות ודעת מינים הרהור עבירה והרהור ע"ז בשלמא הני תלת מפרשן עול מצות דכתיב (במדבר טו, לט) וראיתם אותו וזכרתם את כל מצות ה' ציצית דכתיב ועשו להם ציצית וגו' יציאת מצרים דכתיב אשר הוצאתי וגו' אלא דעת מינים הרהור עבירה והרהור ע"ז מנלן דתניא אחרי לבבכם זו מינות וכן הוא אומר (תהלים יד, א) אמר נבל בלבו אין אלהים אחרי עיניכם זה הרהור עבירה שנאמר (שופטים יד, ג) ויאמר שמשון אל אביו אותה קח לי כי היא ישרה בעיני אתם זונים זה הרהור ע"ז וכן הוא אומר (שופטים ח, לג) ויזנו אחרי הבעלים:
Why was the Parashah of Fringes included [in the Shema']? R. Judah b. Habiba said : Because there are five things contained therein : the command of fringes ; the exodus from Egypt ; the yoke of the commandments ; [a warning against] heretical opinions [Minut] ; lustful imagination and idolatrous longing. Quite right that three of these are explicitly stated therein ; viz. : the yoke of the commandments, as it is written, "That ye may look upon it and remember all the commandments of the Lord" (ibid. xv. 39) ; the command of Fringes, as it is written, "That they make for themselves fringes" (ibid. v. 38) ; the exodus from Egypt, as it is written, "I am the Lord your God, Who brought you out of the land of Egypt to be your God ; I am the Lord your God" (ibid. 5:41). But where is there reference to heretical opinions and lustful imagination and idolatrous longing ? There is a teaching : "After your heart" (ibid. v. 39) means heresy; for thus the Scriptures state, "The fool hath said in his heart, There is no God" (Ps. xiv, 1). "After your own eyes" (Num. I.c.) means lustful imagination ; as it is said, "And Samson said unto his father. Get her for me, for she is pleasing in my eyes" (Judg. xiv. 3). "After which ye use to go astray" (Num. I.c.) means idolatrous longing; for thus the Scriptures state, "The children of Israel again went astray after the Baalim " (Judg. viii. 33).
But Why Tzitzit?
(יב) רַבִּי יוֹסֵי אוֹמֵר, יְהִי מָמוֹן חֲבֵרָךְ חָבִיב עָלֶיךָ כְּשֶׁלָּךְ. וְהַתְקֵן עַצְמָךְ לִלְמוֹד תּוֹרָה, שֶׁאֵינָהּ יְרֻשָּׁה לָךְ. וְכָל מַעֲשֶׂיךָ יִהְיוּ לְשֵׁם שָׁמָיִם:
(12) Rabbi Yosi says: The money of your friend should be as dear to you as your own. Prepare yourself to study Torah, for it is not an inheritance for you. All of your actions should be for the sake of Heaven.
Once we have a spiritual direction, we are able to focus our lives. By aiming for all of our actions to be for the "sake of heaven" we are able to have an anchor and to be more spiritual beings.
This is indicative in the first three elements in the Tzitzit chapter:
1) The Tzitzit enables us to begin that focus, as it's blue thread remind us of heaven.
Techelet is the same word as Tachlit.
Tzitizit is to be compared to the garments of our souls--thoughts and actions and attributes--which we want to connect to out inner self--our essence. Just like we connect out garments to the Tchelet and Tzitzit.
2) Our Exodus is similarly of that nature.
Idea of Exodus is that we are able to make spiritual and moral decisions, something a slave--literally and figuratively cannot do.
3) The Mitzvot are the things in the world of action that this becomes alive.
So, thus, we connect all of out parts to our spiritual anchor.
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The Pitfalls
1) Heresy:
When no spiritual goal, we tend to lose focus and intention, and might come to deny God. We abandon elevated goals and succumb to cheaper aspirations.
2) Base and corrupt actions:
When spiritual and elevated goals are lacking, the soul automatically looks elsewhere. Whatever it can get.
3) Idolatry
Soul is always looking. When it feels bankrupt with heresy and Corrupt actions, it tends to look for spirituality in other places and in all the wrong places.