“Believe in God; Believe in Him with perfect trust. Consider Him as sweeter than the sweetest of earthly joys. Ponder that He is the incomparable One. Reflect on His glory night and day and at all times. Let the constant remembrance of Him fill the interstices of your being. Meditate that, “I am naught--He alone Is.” Let the worship of God be the goal of your life. Whatsoever you think, that you become. Cherish the Lord in the recess of your heart. Everything, everywhere is subject to His Will. Ultimately it will be seen that he is All in All.” Yogaswami
“SivaPeruman is the non-dual Reality. I glory in contemplating that He and I are inseparably linked in Oneness. Whatever one yearns for, that he becomes. Therefore meditate that Thou and He are in unison. Then shall all thy acts pulsate as His acts. The Supreme Reality Is He. He is immanent everywhere. The One has assumed many forms. He is beyond birth and death, transcending time and timelessness; He is eternal, and ever unchanging. The perfection of Truth illumines All. ” Yogaswami
Bodhinatha's Latest Upadeshas: "The Difference in Practice of Theism and Monism" (September 3, 2014)
During a puja we're in Theism, to receive the blessings of the Deity. After a puja we can go within our self in meditation, giving up the idea of an external Deity, Monism. Monistic Theism: Advaita Ishvaravada. Advaita means the Monism; Ishvara means the Theism.
In Shum we use two words that relate to that: shumif and dimfi. First, perfect your Theism. Then become a monist. That's called Saiva Siddhanta; one leads to the other.