1) "Nevertheless the foundation of God standeth sure" (ho mentoi stereos themelios tou theou esteken) “However the firm foundation of God stands," sure, certain; Isaiah 28:16; Acts 4:11-12; 1 Corinthians 3:11; 1 Peter 2:5-8. Jesus Christ is that foundation sure, in securing men from hell and a basis for an honorable life.
2) "Having this seal" (echon ten sphragida tauten) "Having, holding, or containing this (kind of) seal." This seal alludes to the identity of the builder whose name or authority was carved over doors in stone and/or in cornerstones, Deuteronomy 6:9; Deuteronomy 11:20; Revelation 21:14.
THE KING’S FOUNDATION
In the days of the Pharaohs, the royal cartouche was impressed upon each brick that was placed in buildings raised by royal authority. The structure was thus known to have been erected by a certain Pharaoh. Here we have the royal cartouche, of the King of Kings set upon the foundation of the great palace of the Church.
-Charles Spurgeon
3) "The Lord knoweth them that are his" (egno kurios tous ontas autou) "The Lord knew (knoweth) those being of him, his own," sealed by His spirit. His sheep are known and preserved by day and night as well as His church, Numbers 16:5; John 10:14; John 10:27; Ephesians 1:13; Matthew 16:18.
4) "And let everyone that nameth the name of Christ" (kai pas ho onomazon to noma kuriou) "And let everyone naming the name of the Lord (everyone claiming to be a Christian);" let him live a separated life, from worldliness, 1 John 2:15-17; 1 Peter 4:15-16.
5) "Depart from iniquity" (aposteto apo adikias) "Let each stand away, stand off, or be separated from unrighteous conduct or iniquity," Galatians 5:25; 1 Thessalonians 5:22.