Nevertheless, God's solid foundation stands firm, sealed with this inscription: "The Lord knows those who are his," and, "Everyone who confesses the name of the Lord must turn away from wickedness (2 Tim 2:19)."

The important assumption behind this verse is that all believers are chosen as priests. Peter also speaks of the same truth in his second letter. He first calls Christians as “living stones” being built into a spiritual house, and he encourages them saying:

But you are a chosen people, a royal priesthood, a holy nation, a people belonging to God, that you may declare the praises of him who called you out of darkness into his wonderful light (1 Pet 2:9).

As we have already discussed, the Second Temple built at the time of the prophet Haggai had a stone placed in the Most Holy Place instead of the Ark of the Covenant. This stone was what Paul refers to as “God’s solid foundation.” The story behind it was that of Num 16: Korah and his followers approached God trying to get priesthood in a wrong way. Keep in mind that you need to be a priest in order to be able to see this tone as you enter the Most Holy Place on the Day of Atonement with a censer in your hand. And to be able to serve God in the temple that way, you need to “turn away from wickedness.”

In a large house there are articles not only of gold and silver, but also of wood and clay; some are for noble purposes and some for ignoble. If a man cleanses himself from the latter, he will be an instrument for noble purposes, made holy, useful to the Master and prepared to do any good work (2 Tim 2:20-21).

The holiness of the vessels used in the temple, God’s house, was an essential requirement, which was obviously well known among the priests. So, Paul uses it metaphorically to speak about the holiness that is also required for a believer as a priest—God’s living vessel. This holiness is not only necessary for the short time the priest actually spends serving in the temple, but also for the time he spends living outside the temple. If he goes into the temple with filthiness still lingering on him, he will be killed.

The prophet Zechariah, who was contemporary with Haggai, saw a vision in which Joshua the high priest was standing and being accused by Satan. Then, the Lord said to Satan:

The Lord rebuke you, Satan! The Lord, who has chosen Jerusalem, rebuke you! Is not this man a burning stick snatched from the fire (Zech 3:2)?

In this vision, Joshua metaphorically represented the nation of Israel, and he was redeemed from the loss of the priesthood that he once had. At the time of Exodus, God declared Israel as “a kingdom of priests,” but Jerusalem, together the temple, was burnt, and the nation was destroyed as a result of their sin. In the same way, Adam was created and put in the Garden of Eden to serve God as a priest. But as a result of his sin, he was driven out of the garden and dismissed from his priesthood. However, in the vision, Zechariah saw that the filthy clothes that Joshua wore was removed, and rich priestly garments and a clean turban were given to him, and he was put back in charge of God’s house and courts! How was God really able to do such a thing? The Lord said:

“… I am going to bring my servant, the Branch. See, the stone I have set in front of Joshua! There are seven eyes on that one stone, and I will engrave an inscription on it,” says the Lord Almighty, “and I will remove the sin of this land in a single day (vv. 8-9).”