735. The reason why temptation as regards things of the understanding, that is, as regards the falsities residing with man, is mild is that man is subject to the illusions of the senses; and the illusions of the senses are such that they are bound to enter in, and for this reason they are easily dispersed. This is the case with all who keep to the sense of the letter of the Word, where the statements made are in accordance with man's mental grasp, and so in accordance with the illusions of his senses. If those people in simplicity have faith in these things because it is the Lord's Word, then despite being subject to illusions, they easily allow themselves to be taught. Take, for example, someone who believes that the Lord is angry, punishes, and does evil to the wicked; because he has acquired this from the sense of the letter he can easily be taught the truth of the matter. Equally, if in simplicity he believes that of himself he can do good and that he receives a reward in the next life if he is a good man of himself, he also can easily be taught that the good he does comes from the Lord and that the Lord out of His mercy grants the reward for nothing. Consequently when such people enter into temptation as regards things of the understanding, that is, illusions such as these, they are able to be tempted only mildly. It is this initial temptation, scarcely seeming to be temptation at all, that is the subject here. The situation is altogether different however with people who do not believe the Word from simplicity of heart but who confirm themselves in illusions and falsities for the reason that these favour their own evil desires. For that reason they accumulate from ideas of their own and from the facts they know many more compelling arguments which they then confirm by means of the Word, and in so doing impress upon themselves and persuade themselves that falsity is truth.

The number "four" in the Bible represents things being linked together or joined. This is partly because four is two times two, and two represents the ultimate linking between our desire to be good and our understanding of truth. We can also see this in the fact that most buildings are rectangular, with the four sides linking together to make a whole. We also divide directions into four -- north, east, south and west -- and talk about the "four corners" of something meaning all of it. So our special thinking naturally looks at four sides as linking together into a whole.

(References: Apocalypse Explained 417; Arcana Coelestia 1686, 9103, 9601, 9767, 9864)