1 Nephi 11:26

The angel says to Nephi, "Look and behold the condescension of God!" Earlier, the angel asks Nephi if he knew what that meant. He said that he did know the meaning of all things. Here is the excerpt for the Institute Book of Mormon manual on the subject:

"In 1 Nephi 11:26 Nephi is taught a second time about the condescension of God. The first time this subject was taught (see v. 16) it was followed by a vision of the birth of the Son of God. The second time it is followed by a vision of Christ’s ministry. Elder Bruce R. McConkie commented on the two different senses of the condescension of God in this way: 'The condescension of God (meaning the Father) consists in the fact that though he is an exalted, perfected, glorified Personage, he became the personal and literal Father of a mortal Offspring born of mortal
woman. And the condescension of God (meaning the Son) consists in the fact that though he himself is the Lord Omnipotent, the very Being who created the earth and all things that in it are, yet being born of mortal woman, he submitted to all the trials of mortality, suffering ‘temptations, and pain of body, hunger, thirst, and fatigue, even more than man can suffer, except it be unto death’ (Mosiah 3:5–8), finally being put to death in a most ignominious manner' (Mormon Doctrine, p. 155)."

Condescension is from the Latin con- which means "with" and descendere which means "to descend." So, in the sense of a heavenly being condescending, I think that Elder McConkie captured the definition and the phenomenon pretty well in the description above.

Why is this important for our day? Well, it is vital that we understand that Jesus Christ was part god and part man. In this way, he was able to be the perfect sacrifice for us. He took upon Himself all the sins, pains, and sorrows that we have, are, and will face. This was able to be done because of His god-like quality. He was able to pass through these feelings like we do/would. This was because of His man-like quality.

In Alma 7:10-12, Alma testifies about this very thing to the people of Gideon. He said, "And he shall go forth, suffering pains and afflictions and temptations of every kind; and this that the word might be fulfilled which saith he will take upon him the pains and the sicknesses of his people." Then we can put our sins and pains on Him, that He can pay the price of the pain and so we do not have to feel it and go through it, if we but ask. What a marvelous thing. We need to be sincere and we cannot let His sacrifice be for not.