The Torah says, "And you shall walk in His ways." Maimonides counts this verse as one of the 613 mitzvot.
He explains that the way to fulfill this mitzvah is by following in God's footsteps and behaving as He does. Just as God is kind, we must act kindly. Just as He is merciful, we must be merciful.
However, this appears to be a general mitzvah. That is, it doesn't involve a specific detail of a Jew's life, like the mitzvah of tefillin, which is fulfilled by placing one prayer on the arm and another on the head, or the mitzvah of mezuzah, which is fulfilled by placing a parchment on the doorposts, etc. Rather, the mitzvah of walking in God's ways applies to all aspects of a person's life.
The rule is that a general mitzvah cannot be counted as one of the 613 mitzvot. So why does Maimonides count it in a special way?
The answer is that this Mitzvah contains a specific teaching in the life of a Jew.
The Torah says, "And you shall walk..." A Jew is commanded to always be walking. Every mitzvah we perform should move us forward in the direction we are meant to go. When we follow God's path and observe His commandments, we should feel that we are changing and becoming better people. And we can and should always keep moving forward because, no matter how far we have come, we can always go further.
Extracted from Please tell me what the Rebbe says.