On Pesach, HKBH freed us from our Egyptian bondage and, on a spiritual level, from our personal boundaries and self-limiting beliefs. We are heading towards Matan Torah (the giving of the Torah on Shavuot, 50 days after Pesach) during this period of Sefirat HaOmer.
This period offers us a unique opportunity to work on improving our midot (character traits). We have particular siyata dishmaya (aid from HKBH above) to grow into who we are at our core, aligning ourselves and our actions with our Godly soul.
Each day provides us with a chance to refine a particular part of ourselves, and over the seven weeks of the Omer period, we become a vessel fit to receive the Torah on Shavuot.