Note 21 at 2 Tim. 2:19: Paul had just cited that some believers had been led astray through the false teachings of Hymenaeus and Philetus. Now he assures Timothy that regardless of how many err, the foundation of God is secure. Jesus is our foundation (Isa. 28:16; 1 Cor. 3:11; Eph. 2:20; 1 Pet. 2:6). Individuals may suffer loss, but the kingdom of God is safe because of its sure foundation-Jesus Christ.

Note 22 at 2 Tim. 2:19: The Greek word that was translated "seal" here is "SPHRAGIS" which means, "a signet (as fencing in or protecting from misappropriation); by impl. the stamp impressed (as a mark of privacy, or genuineness), lit. or fig.:" (Strong). Fritz Rienecker's Linguistic Key to the Greek New Testament says, "The illusion is to the practice of placing on a building, or its foundation stone, an inscription or other sign to indicate its owner's purpose."

This Greek word for "seal" is alluding to validation in contrast with another Greek word that was translated "seal" in Ephesians 1:13, which deals with preservation (see note 23 at Eph. 1:13, p. 1098).

Note 23 at 2 Tim. 2:19: Paul is comparing the kingdom of God in this verse to a mansion or large building. Jesus is the foundation and there is an inscription (seal) written on it that says, ". . .The Lord knoweth them that are his. And, Let every one that nameth the name of Christ depart from iniquity."

Note 24 at 2 Tim. 2:19: This verse is in response to what Paul told Timothy in the previous verse about the faith of some being overthrown because of false doctrines (see note 21 at this v.).

Paul is reassuring Timothy that God's kingdom is strong because of two things: First, the Lord knows everyone who belongs to Him, and second, those who truly know Christ are to depart from evil.

This implies that those who departed were probably not true believers (1 Jn. 2:19).

The next verse strengthens this interpretation. Paul continues the allegory about the kingdom of God being like a house and speaks of vessels that honor and some that dishonor. This is speaking of the kingdom being populated with some genuine believers and others who are not truly born again.