The function of chanted prayers (pujas) is to fill our mind with positive energy, to remove negativity, and to gain inspiration for our meditation practice. Gaining deep experience of compassion and wisdom depends upon certain inner conditions, which we can create by engaging in chanted prayers.
Just as a farmer needs to prepare the ground before he plants his crop, so we need to prepare our mind before we hope to harvest a crop of spiritual realizations. There are many people who are very interested in meditation but who, not understanding the importance of preparing the mind for meditation, become disappointed when their efforts in meditation do not yield results. The better we prepare our mind the more easily our compassion and wisdom will grow. Chanted meditations uplift and heal the mind and help us to develop these positive qualities.