Nirguna Puja
From Hindupedia, the Hindu Encyclopedia
Nirguna puja is practiced by Hindus who don’t offer prayers to God through idols. This bhakti received much momentum beginning in the Bhakti Era wherein prominent personalities like saints Ramananda, Kabir, Ramai Pandit, and Mahima Swami, and several others promulgated this worship.
Today, sects such as, Ekasaranas (Vaishnava), Brahmā Kumaris (Shaiva), and Dharmthakuris exclusively worship this way.