bhaktya tv ananyaya sakya
aham evam-vidho ’rjuna
jnatum drastum ca tattvena
pravestum ca parantapa

"My dear Arjuna, only by undivided devotional service can I be understood as I am, standing before you, and can thus be seen directly. Only in this way can you enter into the mysteries of My understanding."

Arjuna = Arjuna, parantapa = suppressor of enemies, is asked to listen to the words of the Lord. Bhaktya tu = apart from Bhakti , ananyaya = no other, sakya = can, aham = I [Sri Krishna] am, vidho = realizable, jnatum = to understand [the Lord], drastum = to see [the Lord], tattvena = truly, pravestum = to reach [the Lord], Bhakti is necessary. Tattvena means realizing the truth, as we could realize partially or wrongfully. Thus the Lord says that if one wanted to realize or see or fully understand the Lord, then nothing other than Bhakti would be helpful. Bhakti, which we all have is a stage below Parabhakti. We are in none of the Three stages mentioned. We can expect to possess Parabhakti. The ordinary Bhakti we possess occurs because of the good actions we might have done over long periods. This Bhakti alone can draw us near the Lord and will take to Parabhakti. Parabhakti will take to Paragyana, which would take to Paramabhakti. What are these stages? In this sloka the Lord mentions Three words Gyatum, Drastum and Pravestum - realizing, seeing and attaining. These three should be correlated with the Three stages of Bhakti. So, Parabhakti means Gyatum or understanding; Paragyana is Drastum or seeing; and, Paramabhakti is Pravestum or reaching the Lord. Thus Gyana, Darsana and Prapti [ज्ञानं, दर्शनं, प्राप्ति] correspond to the Three stages of Bhakti. First we have to realize the Lord, that is Gyana. Next is to see the Lord, that is Darsanam. Finally, we have to reach Him, that is Prapti. But Bhakti is the basic requirement for all these. Our interest in Him is Bhakti. This only would induce us to realize or understand Him. Then only we will have the eagerness to see Him. Once seeing Him, we would like to reach Him. We are at the basic foundation of Bhakti. Thus Sri Krishna says that by Bhakti alone He is realized. This basic Bhakti takes one to the Three stages above. Normally, we spend our time in unwanted and useless matters. In fact we spend many days without even thinking of the Lord. Our efforts and time are spent in acquring material wealth and worldly pleasures. From these we divert our attention to the Lord and that is the start of Bhakti. This raises some inquisitiveness to know about Him and that is Gyana. By understanding more and more our eagerness to feel and see Him will increase. Thus our love for Him gets converted to eagerness. This eagerness results in seeing Him or Darsanam. Once seen, our mind would never go after anything else, and we want to be with Him. That is, being with Him is pleasure and separated from Him is sorrowful. This stage is Prapti or attaining Him. Thus Bhakti or love is the basic requirement. This concept is in Bhotatalwar's pasuram 'anbe thagaliya அன்பே தகளியா ...'. The foundation of Bhakti is in the word anbe. Next to light this lamp, Alwar says he has eagerness or enthusiasm as the oil [aarvame neyyaaga ஆர்வமே நெய்யாக]. As wick [திரி] is his mind, which is lighted. Thus the Alwar lights and sees Sriman Narayana and reaches Him.