The Symbol of Unleavened Bread
Let every Christian be quite clear about this: You know that Christ has formed a link between your soul and God, that nothing can ever touch it. You have been born of God and washed in the blood of His dear Son, and you are a child of God, and nothing, by His infinite grace, can break that link. But a foolish thought allowed will hinder communion. The very smallest bit of leaven breaks the link of communion, and I am out of the current of the working of the Spirit of God.
Now we know very well that the blessed normal work of the Spirit of God is to bring Christ before our hearts. If something has come in that has broken this tender link of communion between the Lord and our souls, the Spirit of God makes the soul conscious thereof. There comes in a cloud. I must get back and find what was the hindrance, judge it, and then all is right.
Nothing can break the link that grace has formed as a matter of eternal life. But a very small thing can snap the link of communion and rob the soul of the joy and divine delight that God would give us by His Spirit. Therefore you see the immense importance of the unleavened bread, "the unleavened bread of sincerity and truth."