The Lord's Supper is the food of souls...

On this account it is indeed called a food of souls, which nourishes and strengthens the new man.  For by Baptism we are first born anew.  But, as we have said before, there still remains the old vicious nature of flesh and blood in mankind.  There are so many hindrances and temptations of the devil and of the world that we often become weary and faint, and sometimes we also stumble.

Therefore, the Sacrament is given as a daily pasture and sustenance, that faith may refresh and strengthen itself so that it will not fall back in such a battle, but become ever stronger and stronger. The new life must be guided so that it continually increases and progresses.  But it must suffer much opposition.  For the devil is such a furious enemy.  When he sees that we oppose him and attack the old man, and that he cannot topple us over by force, he prowls and moves about on all sides.  He tries every trick and does not stop until he finally wears us out, so that we either renounce our faith or throw up our hands and put up our feet, becoming indifferent or impatient.  Now to this purpose the comfort of the Sacrament is given when the heart feels that the burden is becoming too heavy, so that it may gain here new power and refreshment.
~BOC, LC, V, 24-27

The devil chafes and rages as a fierce enemy against us with all his power and might...

No one can believe how the devil opposes and resists these prayers.  He cannot allow anyone to teach or to believe rightly.  It hurts him beyond measure to have his lies and abominations exposed, which have been honored under the most fancy, sham uses of the divine name.  It hurts him when he himself is disgraced, is driven out of the heart, and has to let a breach be made in his kingdom.  Therefore, he chafes and rages as a fierce enemy with all his power and might.  He marshals all his subjects and, in addition, enlists the world and our own flesh as his allies.  For our flesh is in itself lazy and inclined to evil, even though we have accepted and believe God's Word.  The world, however, is perverse and wicked.  So he provokes the world against us, fans and stirs the fire, so that he may hinder and drive us back, cause us to fall, and again bring us under his power.  Such is all his will, and mind, and thought.  He strives for this day and night and never rests a moment.  He uses all arts, wiles, ways, and means that he can invent.

~BOC, LC, III, 62-64

Every mote of our existence is from God...

For although the whole world should work together, it could not add an hour to our life or give us a single grain from the earth.
~BOC, LC, I, 166

Original sin precludes belief in, fear of, and love for God, as well as seeks fleshly things...

We are right in our description of original sin when we say that it is not being able to believe God and not being able to fear and love God.  We are right when we say that it includes concupiscense, which seeks fleshly things contrary to God's Word.  This means when it seeks not only the pleasures of the body, but also fleshly wisdom and righteousness.
~BOC, AP, II (I), 26

God cannot lie or deceive...

David, on the other hand, was a despised man, hunted down and chased, so that he did not feel his life was secure anywhere.  Yet, he had to survive, in spite of Saul, and become king.  For these words of the promise had to abide and come true, since God cannot lie or deceive.  Just let not the devil and the world deceive you with their show, which indeed remains for a time, but finally is nothing.
~BOC, LC, I, 46