In a copy of the NIV with footnotes written by Charles Ryrie:
The promises were spoken to Abraham and to his seed. The Scripture does not say "and to seeds," meaning many people, but "and to your seed," meaning one person, who is Christ. (NIV)The note on this verse says:
seed. Since Paul's argument here is based on the singular form of the word in the OT (Gen. 22:17-18), he must have believed in the accuracy of the very words of Scripture.Ryrie goes on to use this and another example from Matthew to explain the inerrancy of every word in the Bible—even singular, plural, or tenses of words are important.
However, when we come to 1 Thessalonians 5:23 or Hebrews 4:12,
spirit, soul and body should not be understood as defining the parts of man, but as representing the whole man.Such is the contradiction by those who insist that man is merely two parts—body and soul (which is supposedly the same as the spirit)—and ignore or explain away the many verses in the Bible that speak of the three parts of man. In Greek, spirit is pneuma and soul is psuche, two distinct words. So according to the fact that every word of the Bible is God-breathed and inerrant, soul and spirit should refer to two distinct parts of man. The tendency to confuse the two is even apparent in the translation of the NIV in 1 Thessalonians 5:23 referred to above—the conjunction and is removed from between "spirit" and "soul," although it is unquestionably there in the original Greek text.
More important that simply being correct on this doctrinal point, however, is the idea put forth in the verses from 1 Thessalonians 5 that we must be preserved in all three parts of our being. Verse 23 uses two marvelous words, "(sanctify you) wholly" and "(be preserved) complete," to speak about this preservation. From the footnote, and explained in more depth in Life-study of 1 Thessalonians messages 23 and 24, wholly is quantitative and complete is qualitative. Therefore, we must not only know that we have three parts—spirit, soul, and body—but we must go on to know our three parts and open to the Lord that they be sanctified wholly and preserved completely.