It is important to remark, however, that when the general principle contained in a given passage of Scripture has been once fairly explained, it admits of innumerable applications which are in the highest sense legitimate and proper.  The principle, for example, that “whatsoever is not of faith is sin,” which the apostle Paul announces in connection with the question of using or abstaining from particular kinds of food, may be applied to the settlement of cases of conscience arising in widely different relations and spheres of action.  The preacher’s power lies very much in the ability of unfolding to the understanding and applying to the conscience the general principles involved in the passage of Scripture which he undertakes to expound.

5.  We may next consider the help to be derived from parallel passages.  The ordinary division of parallelisms is into verbal and real:  verbal, where the same word or phrase occurs; real, where the same thought is expressed or the same subject discussed.  Verbal parallelisms often shed much light on the meaning of particular words or phrases, because what is obscure in one passage is made plain in another by some explanatory addition.

An example is the use of the expression my glory (English version, my honor), in Gen. 49:6:  “O my soul, come not thou into their secret” (their secret conclave); “unto their assembly, my glory, be not thou united.”  A comparison of the parallel passages, Psa. 7:5; 16:9; 30:12; 57:8; 108:1, leads to the conclusion that in such a connection the expression is substantially equivalent to my soul, the soul being made in the image of God, and thus the seat of man’s glory.  By a like process of comparison, we arrive at the true signification of the phrase, “the righteousness of God,” or more fully, “the righteousness which is of God by faith” when used with reference to the way of salvation through Christ; at the meaning of the Greek terms translated “propitiation,” etc.  In the same way, as already remarked (No. 1, above), the interpreter ascertains the different significations in which words are employed, and determines which of these is appropriate to any given passage.

Real parallelisms are subdivided, again, into doctrinal and historic; doctrinal, where the same truth is inculcated; historic, where the same event or series of events is recorded.  The supreme importance of doctrinal parallelisms will appear most fully when we come to look at revelation on the divine side, as constituting a grand system of truth harmonious in all its parts.  At present we regard them simply as among the means of ascertaining the sense of a given passage.  Presuming that every author means to be self-consistent, it is our custom to place side by side his different statements which relate to the same subject, that they may mutually explain each other.  The same reasonable method