"Balarama is Nityananda. Vrajendra-nandana yei, saci-suta haila sei, balarama ha-ila nitai. This bala -- Balarama -- comes with Sri Caitanya Mahaprabhu, and both of Them are so merciful that in this age of Kali one may very easily take shelter of Their lotus feet. They come especially to deliver the fallen souls of this age. papi tapi yata chila, hari-name uddharila. Their weapon is sankirtana, hari-nama. Thus one should accept the sword of knowledge from Krishna and be strong with the mercy of Balarama. We are therefore worshiping Krishna-Balarama in Vrindavana. In the Mundaka Upanishad (3.2.4) it is said:
nayam atma bala-hinena labhyo
na ca pramadat tapaso vapy alingat
etair upayair yatate yas tu vidvams
tasyaisha atma visate brahma-dhama
"One cannot attain the goal of life without the mercy of Balarama. Sri Narottama dasa Thakura therefore says, nitaiyera karuna habe, vraje radha-krishna pabe: when one receives the mercy of Balarama, Nityananda, one can attain the lotus feet of Radha and Krishna very easily."
(Srimad-Bhagavatam 7.15.45, Purport)