In Ephesians 2:19-22, in the Phillips translation, the apostle Paul writes:

So you are no longer outsiders or aliens, but fellow-citizens with every other Christian [the saints, NKJV] - you belong now to the household of God. Firmly beneath you is the foundation, God's messengers and prophets, the corner-stone being Christ Jesus himself. In him each separate piece of building, properly fitting into its neighbor, grows together into a temple consecrated to the Lord. You are all part of this building in which God himself lives by his Spirit.

We stand on the Christian lives of those who have gone before us. Those who have died in the faith, the saints who await their resurrection from the dead, form the foundation on which we stand, along with Christ, the Cornerstone. If we live our lives with integrity, then we too become an integral piece of the Temple.

Paul's main intention in Ephesians 2 is to let Gentile converts know that they have equal privileges with Israelite converts. Whatever his origins, each individual forms a separate piece of the "building," and all fitted together provide a habitation for God. The building metaphor is equally appropriate for us. Each of us comes from a different social and ethnic background, education, life experience, and so on. In order for us to become part of the Temple, a place where God dwells, integrity must reside in our characters.

Continuing the metaphor, each of us is fitted into the proper place. If a building is constructed of solid pieces - no rotted or bowed wood, no rusted metal, no inferior materials of any type - and if it is erected on a solid foundation, the result is a structure with integrity. The apostle Peter also uses the building metaphor in I Peter 2:1-5:

Therefore, laying aside all malice, all deceit, hypocrisy, envy, and all evil speaking, as newborn babes, desire the pure milk of the word, that you may grow thereby, if indeed you have tasted that the Lord is gracious. Coming to Him as to a living stone, rejected indeed by men, but chosen by God and precious, you also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ.

A building block or stone, used to construct a spiritual house or a temple, must be sound. It must itself have integrity. If the stone is weak, it will crumble or crack easily, endangering the whole building.