In order to take God at His word, we must strive against all our deep-rooted wickedness. For our natures are so prone to unbelief, that unless we struggle against the sin that ensnares us, we will never trust or cherish in our hearts a single word that God has uttered. This is why each one of us needs to be aware of what we are by nature when we come to be instructed in the Word of God. The, knowing that we are full of rebellion and doubt, we must forsake all of this, asking God to touch our hearts in such a way that they heed what they hear. Indeed, it is the office of the Holy Spirit to take the truth and seal it within our hearts; for although it is true in and of itself, we do not believe it until it is confirmed by the Holy Spirit from on high. Indeed, if we were naturally inclined to believe in God, there would be no need for the Holy Spirit to work within in. He is the true seal by which God sets us apart, and through whom he engraves and imprints in our hearts what we otherwise would never have believed (2 Cor. 1:22; Eph. 1:13).
Notice Paul uses two terms here: he says that no one can 'disannul' or reverse what has been agreed amongst men in a legitimate and valid manner, but he also says that no one can 'add' anything. For even if we were not in the least rebellious, our hearts are so restless that we would make additions to the Word of God, being unable to keep to it in its simplicity. Here, then, are two sinful tendencies that are to be found in all of us if we only examined ourselves as we are, without self-flattery. Firstly, we cannot fully resolve within ourselves honestly and unreservedly to say 'Amen!' to what God has declared nor to accept His promises, nor be fearful of His threatenings. Men always hide behind excuses; we need not go too far to find plentiful examples of this, for as I have said, the tendency is within each one of us! Secondly, though we may render to God His due honor by believing His Word to be true and without error, yet we have a desire to add to it.
This is exemplified in Popery! Why is there such confusion and such a multiplicity of ways of worshipping God? Why are there so many abuses and false practices? It is because men have not submitted to the commandments of God, but instead, have added to them, creating a confused mass of rituals devised in their own minds. Papists strive to serve God, but in what manner? Each of them has his own form of devotion, accompanied by an infinite amount of tomfoolery! They tell us that it has all been appointed by the church, whereas we know it has all been concocted by men! Why should this be? Has not God revealed to us what is pleasing to Him? He tells us that His law is perfect, and that we need no other rule of life. He also informs us that He prefers obedience to all the sacrifices in the world (1 Sam. 15:22; Hos. 6:6; Matt. 9:13; 12:7). The law was designed to bridle man so that he would not presume to add ideas and opinions of his own. God has indeed spoken, yet we add a hundred things which He has not commanded and strictly ordained, and exalt in its place such vain and frivolous nonsense, which not only is of no value in God's sight, but is an abomination. He disapproves of and, indeed, despises anything that man has introduced.
The fact that men seek to worship God according to their own tastes, reveals the lust and excessive pride which has always been part of human nature. Such worship flies in the face of Holy Scripture. For God tells us that the chief sacrifice He demands is for us to cast ourselves upon Him, presenting to Him our requests. After all, He has provided a way for us to come to Him personally and with complete liberty - for He has given us the Lord Jesus Christ as our Advocate. But men would have us call upon dead saints in order to obtain favor with God; they are supposed to be interceding for us as our patrons and advocates! The same applies to other doctrines. God has directed us to pray for one another, but they tell us we must pray for the poor souls in purgatory! And who has commanded this? Men believe this to be a good idea, and notice that what man has commanded is swiftly obeyed! How audacious! God has ordained the sacraments in order to confirm His promises to us, as pledges of His abundant mercy, and to strengthen our weak faith. We have baptism, whereby God declares that we are washed and cleansed from all our sinful stains by the blood shed by His only Son. Now He accepts us as members of His body and we may join His church. But the Papists are not content with such simplicity: they prefer ornaments and candles, and other such nonsense: it is enough to horrify us! And where does all this spring from but devil-inspired audacity? To think that God has established and set down all that is pleasing and fitting in His sight, which we cannot gainsay, and here we are refusing to accept it! But as I have said, the lust of man us such that when it is stirred, he must relentlessly add, mix, change, obscure and confuse.