radha-krishna-pranaya-vikritir hladhini saktir asmad/ekatmanav api bhuvi pura deha-bhedam gatau tau/caitanyakhyam prakatam adhuna tad-dvayam caikyam aptam/ radha-bhava-dyuti-suvalitam naumi krishna-svarupam

‘The loving affairs of Sri Radha and Krishna are transcendental manifestations of the Lord’s internal pleasure-giving potency.  Although Radha and Krishna are one in Their identity, They separated Themselves eternally.  Now these two transcendental identities have again united in the form of Sri Krishna Caitanya.  I bow down to Him, who has manifested Himself with the sentiment and complexion of Srimati Radharani although He is Krishna Himself’ [Caitanya Caritamrita Adi-lila 1.5]

radha – of Srimati Radharani; bhava – mood; dyuti – the lustre; su-valitam – who is adorned with; krishna-svarupam – who is identical with Sri Krishna

‘Radha-Krishna is one.  Radha-Krishna is Krishna and Krishna’s pleasure-giving potency combined.  When Krishna exhibits His pleasure potency, He appears to be two – Radha and Krishna.  Otherwise, Radha and Krishna are one.  This oneness may be perceived by advanced devotees through the grace of Sri Caitanya Mahaprabhu.  This was the case with Ramananda Raya.  One may aspire to attain such a position but one should not try to imitate the maha-bhagavata‘ [CC Madhya-lila 8.282 Purport]