How do we know of the spiritual abodes since once going there no one returns?

Expressions researched:
"how do we know of the spiritual abodes since once going there no one returns"

1969 Correspondence

You should know that the great liberated souls and incarnations who appear from time to time in this material world are not actually coming back, because they are never subject to material contamination or the laws of material nature. For the purpose of delivering the fallen living entities they come here temporarily and then go back when their business is finished, and this is all under the direct order of the Lord.

Letter to Vrndavanesvari -- New Vrindaban 6 June, 1969:

Regarding the first question in your letter about how do we know of the spiritual abodes since once going there no one returns, you should know that the great liberated souls and incarnations who appear from time to time in this material world are not actually coming back, because they are never subject to material contamination or the laws of material nature. For the purpose of delivering the fallen living entities they come here temporarily and then go back when their business is finished, and this is all under the direct order of the Lord. So the appearance of the Lord or the great liberated souls in the material is different from the appearance of the contaminated living entity who is forced to take birth in the material world due to his desire to lord it over the world. In your second question you asked if we will remember the earth, when in Vrindaban, and the answer is certainly. When Narada Muni was talking to Vyasadeva, as you may have read in first volume of our Srimad-Bhagavatam, he was in a spiritual body, but he remembered his previous life and explained it to Vyasadeva. In material life there is forgetfulness, but in spiritual life there is no forgetfulness. I hope this will sufficiently answer these questions for you.