2:19 Even though some in the church were upsetting and being upset, the church itself had stood and would continue to stand firm (Gr. perfect tense; cf. vv. 20-21; 1 Cor. 3:10-12; Eph. 2:20-22; 1 Tim. 3:15). The witness (seal) to this was the truth contained in two passages from the Old Testament (Num. 16:5, and Isa. 52:11 or possibly Num. 16:26; cf. Joel 3:5). The first passage assures that God differentiates between His faithful servants and those who are unfaithful. The second calls on those who identify themselves with the Lord to abstain from wicked behavior. Seals in New Testament times indicated ownership, security, and authenticity.
"What is intended is the seal' of ownership that the architect or owner would have inscribed on the foundation stone (similar in some ways to our modern cornerstones)."48
2:20-21 Paul employed a different illustration to emphasize the same point. In the church there are individuals who honor the Lord as a result of their dedication to follow His truth. These people are useful to the Lord in His work because their commitment to His Word prepares them for His service. However there are also Christians who because of their lack of commitment to God's truth bring dishonor on Him while they seek to be His instruments of service (e.g., false teachers). If someone avoids the defilement of this second group (v. 16), he or she can be a member of the first group (cf. Rom. 9:21).
The major argument for identifying the "large house"as the church is the context. Paul was speaking of faithful and unfaithful Christians.49
