Don't try to see Krsna. You cannot see Krsna with your material eyes. Neither you can hear about Him with your material ears. Neither you can touch. But if you engage your tongue in the service of the Lord, then He'll reveal Himself to you: "Here I am." That is wanted. So feel separation of Krsna just like Radharani, as Lord Caitanya teaches us, and engage your tongue in the service of the Lord; then, one day, when you are mature, you'll see Krsna eye to eye.

Srila Prabhupada, speaking on Radhastami,  Srimati Radharani's Appearance Day — London, August 29, 1971