517. Instruction in the heavens differs from instruction on earth in that knowledges are not committed to memory, but to life; for the memory of spirits is in their life, for they receive and imbibe everything that is in harmony with their life, and do not receive, still less imbibe, what is not in harmony with it; for spirits are affections, and are therefore in a human form that is similar to their affections.  Being such they are constantly animated by an affection for truth that looks to the uses of life; for the Lord provides for everyone's loving the uses suited to his genius; and that love is exalted by the hope of becoming an angel. And as all the uses of heaven have relation to the general use, which is the good of the Lord's kingdom, which in heaven is the fatherland, and as all special and particular uses are to be valued in proportion as they more closely and fully have regard to that general use, so all of these special and particular uses, which are innumerable, are good and heavenly; therefore in everyone an affection for truth is so conjoined with an affection for use that the two make one; and thereby truth is so implanted in use that the truths they acquire are truths of use. In this way are angelic spirits taught and prepared for heaven.  An affection for truth that is suited to the use is insinuated by various means, most of which are unknown in the world; chiefly by representatives of uses which in the spiritual world are exhibited in a thousand ways, and with such delights and pleasures that they permeate the spirit from the interiors of its mind to the exteriors of its body, and thus affect the whole; and in consequence the spirit becomes as it were his use; and therefore when he comes into his society, into which he is initiated by instruction, he is in his life by being in his use.# From all this it is clear that knowledges, which are external truths, do not bring any one into heaven; but the life itself, which is a life of uses implanted by means of knowledges. # Every good has both its delight and its quality from uses and in accordance with uses; therefore such as the good is such the use is (n. 3049, 4984, 7038). Angelic life consists in the goods of love and charity, thus in performing uses (n. 454). The Lord and therefore the angels, have regard to nothing in man but ends which are uses (n. 1317, 1645, 5854). The kingdom of the Lord is a kingdom of uses (n. 454, 696, 1103, 3645, 4054, 7038). Serving the Lord is performing uses (n. 7038). What man is, such are his uses (n. 1568, 3570, 4054, 6571, 6935, 6938, 10284).