And as they were eating, Jesus took bread, blessed and broke it, and gave it to the disciples and said, “Take, eat; this is My body.” Matthew 26:26 
The sacrament is nothing else but a visible word. As often as you see it, you will no sooner see the bread with your eye than the body of Christ will come into your mind. You will no sooner see the wine, than (with the preaching and exposition of the sacrament) the blood of Christ will come into your mind. In the sacrament, the sign and the things signified are offered both together, received together at the same time, and in the same action: the one outwardly, the other inwardly, if you have a mouth in your soul (which is faith) to receive it.
By following and preferring our own pleasures to Christ and His counsel, we have made the stomachs of our souls so bad and ill disposed that they do not receive Him at all; or if He is received, He is not able to tarry. If Christ is not eaten and digested, He can do us no good, but this digestion cannot exist where there is not a greedy appetite to receive Him. If you are not hungry for Him, He is not ready for you. I am sure that if everybody in this country were examined by this rule, few would be found to receive Him.
What is the cause of this? I will tell you. Although we have renounced the corporal and gross idolatry in which our fathers were drowned and immersed, and which in some parts men still seek to establish,  yet as our way of living in this country testifies, there is scarcely a man who has renounced that damnable idol that he has in his own soul, or the invisible idolatry that he has in his own heart and mind. Do not be surprised, therefore, when you have yielded your service, given your affection, and poured out your heart to that pleasure of yours (your idol, your own lust and mischief) – do not be surprised, then, if you have no appetite for Christ or for that heavenly food.
Therefore, let everyone in his own rank think of his own domestic idol, which lodges within his own heart, and strive to rid himself of it. Otherwise, you cannot see the face of Christ to be a partaker of His kingdom. There is no other lesson in Christianity than this; this is the first and the last lesson: to shake off your lust and affections more and more, and so more and more to renounce yourself that you may embrace Christ. I grant that there is greater progress in this with some than with others. Some profit less, some more in this. But unless in some measure you cast off yourselves (and whatever you count most precious in your eyes) in order to come to Christ, you are not worthy of Him. This is very hard to do. It is very easy to speak of it, to bid a man to renounce his own idol, but it is not done so soon. Assuredly, one stronger than the devil must come in to drive out the devil, who makes his residence in the affections. Otherwise, he will remain there forever. There are not many, therefore, who have renounced themselves.
Examine your own heart: if there is anything in the world you love better than Christ, if you are not ready to leave father and mother, to leave wife and children, or whatever is most dear to you in this world for Christ’s sake, you are not worthy of Him. If you are not ready to cast off whatever estranges you from Christ, you are not worthy of Him.
Therefore, it is most necessary that every man should take heed to himself, for the devil is so crafty in regard to this that he is always erecting some idol or other in our souls, and sometimes under the guise of virtue, which is the most dangerous of them all. In every work that we undertake, even the holiest, he is at our right hand. Even in your best moments, when you are engaged in your most virtuous acts, he mixes them with sins, and does all he can to make you lose your profit and lose your reward. For when you are best occupied, he seeks to engender in you an [arrogant] opinion of yourselves and so to defraud God of His glory. Or, on the other hand, he makes you so slack and negligent in doing good deeds that if you do them, you do them coldly, and with such lack of discernment that you are primarily concerned with what is of least importance, and you leave the most important things to the last, like Martha [Luke 10:38-42]. We cannot therefore be watchful enough, always striving to cast out the devil, to renounce ourselves, and to submit to the obedience of Christ.
The Southfield Reformed Presbyterian Church (RPCNA) is scheduled to observe the sacrament of the Lord’s Supper on July 13, 2014 at 2pm. Those desiring to commune who are not communicant members in good standing of the Reformed Presbyterian Church must first be interviewed by the elders as to their personal faith and commitment to Christ, their church membership, and their baptism. In addition, all communicants are urged to engage in private self-examination and preparation beforehand, as mandated by the apostle Paul (1 Cor. 11:27-32) and described in our Larger Catechism (Questions 171-174).
May the Lord renew our hunger and thirst for His grace, that we might cry out to Him in faith: “Hide Your face from my sins, and blot out all my iniquities. Create in me a clean heart, O God, and renew a steadfast spirit within me.” (Psalm 51:9-10)
 Material excerpted and adapted from The Mystery of the Lord’s Supper: Sermons by Robert Bruce (Rutherford House: Edinburgh, 2005) 44-53.
 This is a reference to the Roman Catholic mass.