Picking back up with the sins forbidden by the Second Commandment, then...
Making any representation of God, worshiping such graven images, and worshiping God by such images.
God forbids trying to capture the Lord God in any mental or visual images, for such efforts are a contradiction of His uncreated, immaterial and infinite spirituality, a rejection of God’s sovereignty, a denial of His incomparable majesty, and represent attempts to control God by magic. (129)
Mental pictures of images of God are idolatrous. God is to be perceived in His perfections and works, not in terms of a specific form or shape, even mentally. (130)
It should be obvious that giving such mental images or visual images the worship, adoration, veneration or honor that belongs alone to God is idolatry, and idolatry that is an abomination to the living God, who is jealous for His own glory. (132)
Although it is obvious that graven images should not be worshipped, it is not as obvious that all worshipping of God by means of, or represented, in or symbolized by such graven images is also idolatry... Aaron had no intention of leading Israel to worship another god than Jehovah, or of worshipping the golden calf, but of worshipping Jehovah by means of and as symbolized in the golden calf. (133)
Why is this desire [to worship God with images] evil? (1) It is rooted in unbelief. Faith rests in the sheer Word of God without any other props. If God says He is
near His people, faith believes God. (2) It is an attempt to control God and to guarantee His presence with His people. (3) Worshipping God by means of a graven image promptly turns into the worshipping of the graven image as God. (134)
The Second Commandment forbids using images as pretended helps to worship, because no feigned images of God, Father, Son or Spirit, are at all helpful in the worship of God, rather they are hindrances to true worship. (140)
Representation of feigned deities give a false appearance, are a pretense and a sham.
Superstitious devices are those ceremonies and rites invented by the brain of man, not commanded by God, used to manipulate the supposed “dark supernatural forces, ” e.g., lucky charms, or used in the worship of the true God, e.g., kneeling to receive communion, clerical vestments and prayers for, or to, the dead. In whatever sense we use the phrase, superstitious devices, all of them are forbidden by God. (142)
We should notice five emphases in this text [Is. 1:10-15]: (1) The Divine disgust for religious rites without repentance; (2) The “heartless” but sincere worship of Judah; (3) The hatred of God’s “soul” for worship without heart; (4) The burden of superstitious worship to God; and (5) The refusal of God to hear and answer prayer in superstitious worship. (143)
 In her apostate condition Israel’s worship, prayers, religious rites and holy days meant nothing to Jehovah. In fact, He was repulsed by their observance, frequency and sincerity. Although He had commanded that these things be done in His worship, He never commanded these religious rites apart from repentance and integrity of heart before Him (1 Sam. 15:22; Jer. 6:20; Hos. 6:6; Amos 5:21–23).
The sacrifices, prayers and holy days had been prescribed by Jehovah, but not without faith in the heart. (143)
 The worshippers in Judah and Jerusalem were generally correct in their worship practices and they may have been enthusiastic and sincere in the performing of them, but sincerity, enthusiasm, and external correctness are no substitutes for obedience to God’s commands from the heart and in the life. (144)
 He hates apostate, superstitious worship. “My soul” is an anthropomorphic
expression which means much more than merely a substitute for the personal pronoun “I.” “My soul” is “the center of His being, regarded as encircled and pervaded by self-consciousness." 200. Delitzsch, quoted in Young, The Book of Isaiah, 1:67. (145)
 Superstitious worship, then, according to this text is comprised of two things: (1) Worshipping God in a manner not commanded by God; and (2) Worshipping God when in the worshipper’s heart there is no living faith in God. This merely formal, although sincere, worship is seen as a burden resting heavily on the Lord. (145)
 Isaiah 1 teaches us that the prayers and worship of apostates, however externally correct and sincere, are rejected by Jehovah, because fervor and zeal in prayer and worship are no substitutes for faith and obedience. (147)
The people and priests of Israel were corrupting the worship of God during Malachi’s day by “presenting defiled food on My [God’s] altar,” i.e., by presenting blind and lame and sick animals to be sacrificed rather than perfect and unblemished animals and by offering unsuitable and coarse bread, probably dry and moldy, to be placed on the “table of showbread” in the Temple. (155)
The people were defiling God’s altar and despising His name by being convinced that they needed to offer sacrifices to God to secure His blessing, and yet by being careless and negligent and disobedient in offering sacrifices that were not exactly what God commanded....They were trying to secure God’s favor by a general correctness in the externals of worship, but for them it was not worth the effort to be carefully and painstakingly obedient to God’s ordinances from the heart. (156)
The priests were particularly defiling God’s altar and despising His name by being wicked and sacrilegious in their corrupting of God’s worship, while suppressing any consciousness of doing anything wrong (1:6). In fact, God’s reproofs through Malachi are primarily directed to the priests, because they allowed and encouraged
the people to corrupt their worship of God by offering the corrupted animals and bread the people brought. (157)
So then, by corrupting the worship of God, the Larger Catechism is describing such sins as half-heartedness and hypocrisy in the worship of God, failure to see the value of strictness of observance of God’s revealed ordinances of worship, giving to God less than our best and highest devotion, holding anything or anybody as more precious to us than the worship of the triune God. (161)
The text of covenant Law God has given His people is not to be tampered with, for it is the revelation of the will of Jehovah, their Lord and Savior. It is to be accepted as given by Him without amendment or abridgement by human legislation. Without lessening God’s demands, by obeying only part of them, or increasing God’s demands by the addition of human laws, God’s people are to submit themselves entirely to the inviolable Word of God, lest they detract from the majesty of God’s Law, which is a “testimony” of the glorious character of God. (163)
Any addition to the Law of God is forbidden by Deuteronomy ed and taken up of ourselves, and therefore such “practices” makes those who use them “unclean” in God’s sight. Some people invent ways of worshipping God for themselves personally without any desire to impose them on others or to make them public. Even these practices in personal and private worship are forbidden.
Such “practices” make us “unclean,” for placing our own personal practices alongside the Law is not only the height of arrogance, it has the effect of invalidating the Law of God (Mark 7) and is in God’s sight spiritual prostitution, i.e., unfaithfulness to our covenantal Husband and Bridegroom to whom we have pledged our total, life-long, unqualified, and undivided submission to love and
obey: “they played the harlot in their deeds.” (164-165)
Even if these worship rituals invented by man without Divine sanction are received by tradition from others, with a long and distinguished history in the church, they are dishonoring to God and hence forbidden....(1) They make true worship empty and vain: “in vain do they worship Me.” (2) They are the “precepts of men, the tradition of men, your tradition which you handed down,” rather than the commandment of God. (3) The keeping of such traditions causes the “neglecting of the commandment of God,” “nicely set[ting] aside the commandment of God,” and “invalidating the Word of God.” (166)
1] Nor does it matter that man-made worship rituals have the title of antiquity, i.e., they have a long and celebrated history, “inherited from your forefathers;” the passage of time does not make good evil or evil good. It is evil to supplement, amend or abridge the Law of God and it is never right to do so, nor will it ever be right, and although such things have been approved by many for centuries, it has never been right. (166-167)
Even if these human inventions are venerated as the established customs of a religious society, which most of the people followed, along with the rich, powerful, prestigious and famous, they are still forbidden by the Word of God. (167)
Neither religious zeal, sacrificing devotion, utter sincerity nor enthusiastic passion for the worship of God can justify any innovations in worship not sanctioned by God’s command in the Bible. (174)
God accepts no honoring or worshipping of Him, however “good” our intentions, “without it having the express commandment of his own word to be done in all points.” 253. Knox, Selected Writings of John Knox, 24 (179)