It is a mitzvah in The Torah that every single individual should have his or her own Torah scroll. This appears to be a difficult mitzvah to perform as a Torah scroll can range into the tens of thousands. However, as we know, if even one letter is missing from a Torah, G-d forbid, then the entire scroll is deemed non kosher. For that reason, every single letter is as if it is an entire scroll. Today we can fulfill the mitzvah by not only having an entire scroll written, but by having a parasha, pasuk or letter written in your merit.
We will have a letter, verse or a whole parasha in a Sefer Torah that will be written for you or the memory of your beloved ones.