Iniquity of the Holy Things

"And it shall be upon Aaron's forehead, that Aaron may bear the iniquity of the holy things, which the children of Israel shall hallow in all their holy gifts; and it shall be always upon his forehead, that they may be accepted before the LORD" (Exodus 28:38).

Iniquity of the holy things? What a humbling and awesome thought.

"What a veil is lifted up by these words, and what a disclosure is made! It will be humbling and profitable for us to pause awhile and see this sad sight. The iniquities of our public worship, its hypocrisy, formality, lukewarmness, irreverence, wandering of heart and forgetfulness of God, what a full measure have we there! Our work for the Lord, its emulation, selfishness, carelessness, slackness, unbelief, what a mass of defilement is there! Our private devotions, their laxity, coldness, neglect, sleepiness, and vanity, what a mountain of dead earth is there! If we looked more carefully we should find this iniquity to be far greater than appears at first sight." -- Charles H. Spurgeon.

"It is undoubtedly a remarkable passage, whereby, we are taught that nothing proceeds from us pleasing to God except through the intervention of the grace of the Mediator; for here there is no reference to manifest and gross sins, the pardon of which it is clear that we can only obtain through Christ; but the iniquity of the holy oblations was to be taken away and cleansed by the priest.... This is a harsh saying, and almost a paradox, that our very holinesses are so impure as to need pardon; but it must be borne in mind that nothing is so pure as not to contract some stain from us; just as water, which, although it may be drawn in purity from a limpid fountain, yet, if it passes over muddy ground, is tinged by it, and becomes somewhat turbid: thus nothing is so pure in itself as not to be polluted by the contagion of our flesh. Nothing is more excellent than the service of God; and yet the people could offer nothing, even although prescribed by the Law, except with the intervention of pardon, which none but the priest could obtain for them. There is now no sacrifice, nor was there ever, more pleasing to God than the invocation of His name, as He himself declares, 'Call upon me in the day of trouble: I will deliver thee, and thou shalt glorify me,' (Psalm 1:15;) yet the Apostle teaches us that 'the sacrifice of praise' only pleases God when it is offered in Christ. (Hebrews 13:15.) Let us learn, then, that our acts of obedience, when they come into God’s sight, are mingled with iniquity, which exposes us to His judgment, unless Christ should sanctify them. In sum, this passage teaches us that whatsoever good works we strive to present to God are so far from deserving reward, that they rather convict us of guilt, unless the holiness of Christ, whereby God is propitiated, obtains pardon for them." -- John Calvin.

So, even in the "holy things," the commanded acts of God's worship, we offer up nothing that is not tainted by our iniquity. Thanks be to God for Christ our High Priest! My question is, if this is true of the worship commanded by God (which are holy things), what of man-invented worship (which cannot be holy things)? Is it not 100% pure filth?