On the Last Day of Unleavened Bread, when the frightened Israelites had their backs to the Red Sea, Moses commanded them not to fear, but to stand still and to witness God's deliverance as the walls of the Red Sea protected His emancipated slaves. A similar set of watery walls emerged, allowing Joshua to bring the Israelites across the Jordan River. A wall is a symbol of protection or salvation. Because Jerusalem's walls had become breached during the Babylonic captivity, the land of Judah was vulnerable to attack. Nehemiah's acquired favor of the king enabled a remnant to return to rebuild the walls. Similarly, the church (the Israel of God) must keep a protective wall to protect against scattering and assimilation. Almighty God's called-out saints can assist in building protective walls by making sacrifices, motivated by His Holy Spirit, revealing the true value of the things that God has freely given. Only His Spirit can enable us to apprehend or appraise the value of spiritual wealth which the carnal man does not understand. Our sacrifices and offerings must be motivated by the mind of Christ, able to evaluate properly the incredible wealth God has given us. In Deuteronomy 16:16, the offering is purely a personal decision between God and the offeror, but the appraisal can only be factored with a spiritual rather than a physical evaluation.