The Hebrew word for phylacteries (teffilin) comes from the same root as the word tefilah, which is commonly mistranslated as prayer. The root of the words tefilah and teffilin  creates the verb lehitpalel, which means to change oneself. That is, tefilah and teffilin are both words that describe a person who is in the process of aligning their mind and heart with God by changing themselves; tefilah and teffilin both allow a person to-feel-in tune with God and His creation.