To build something generally means to put together a variety of simpler pieces to make a useful and more complex structure, as to build a house out of wood or bricks, and it is commonly used this way in the Word. In the land of Shinar men wished to build a tower, and in the new testament Jesus advised that a wise man should build his house on a rock. But in a representative sense the meaning is to build a mental and spiritual structure, like the doctrine of a church or the individual concepts of spiritual reality in a single mind. The building materials are representative also. The tower of Babel was built of brick, which is man-made rock, or representatively, man-made "truths", that is"truths" not from God but ideas of spiritual reality thought out by men. The house that the wise man would build was founded on a natural or "God-made" rock, which means a truth from the Word.

375. (ii) Charity and faith are merely unstable mental concepts unless, when possible, they are realised in deeds and come into existence together in them.

Does not man possess a head and a body, which are linked by a neck? Does not the head contain a mind which wills and thinks, and the body a potentiality which performs and executes actions? So if a person merely had a good will, or thought from charity without doing good and performing useful deeds as a result of charity, would he not be like an isolated head or mind, which lacking a body could not continue in existence alone? Who from this can fail to see that charity and faith are not charity and faith, so long as they are only in the head and mind, and not in the body? Then they are like birds flying through the air without anywhere to rest upon the ground; and also like birds carrying eggs without nests to lay them in, so that their eggs would be discharged into the air or on a branch of a tree, and so would fall to the ground and be broken.

[2] There is nothing in the mind which does not have a corresponding part in the body, and this corresponding part can be called the embodiment of what is in the mind. Charity and faith therefore, so long as they are in the mind, have no embodiment in the person, and they can then be likened to an airy phantom, what is called a ghost, much as Fame was depicted by the ancients with a laurel wreath around her head and a horn of plenty in her hand. Since they are such ghosts, though still able to think, they cannot help being excited by fantastic ideas, a result also produced by reasoning from various sophistries; very much as reeds in marshes are shaken by the wind, while on the bottom below them lie shells and on the surface frogs croak. Can anyone fail to see that such are the results of merely knowing some things from the Word about charity and faith without practising them? The Lord also says:

Everyone who hears my words and acts upon them, I will compare to a prudent man, who built his house upon a rock; but everyone who hears my words and does not act upon them will be compared to a foolish man, who built his house upon sand or on ground without a foundation, Matthew 7:24, 26; Luke 6:47-49.

Charity and faith together with their invented ideas, when a person does not put them into practice, can also be compared with butterflies on the wing, which a sparrow on seeing swoops on and swallows. The Lord also says:

A sower went out to sow; and some seeds fell on the hard path, and the birds came and ate them up, Matthew 13:3-4.