Unusually, the text gives us not only the law but also its rationale: “You shall put fringes on the corners of your garments… that you may look at it (the fringe) and be reminded of all the commandments of the Lord”.
It has been suggested that the Hebrew oto, usually translated “it” (the fringe) can also be understood as “Him” and be a reference to God. In other words, by looking at the tzitzit one has in a sense a mystical experience and sees the Almighty.
Of course this cannot be taken literally, since God has no physical shape or form, but through looking at the fringe one is reminded of the Divine commandments and as it were one perceives God through the mitzvot which are His messengers.
The mitzvah of kashrut is God telling us that holiness is not merely an internal spiritual feeling but must be expressed in normal day-to-day life; the mitzvah of Shabbat is God urging us to sanctify time; the mitzvah of charity is God insisting that we love and support our fellow human beings.