28. Baptism and the Lord's Supper
Baptism and the Lord's Supper are ordinances of positive and sovereign institution, appointed by the Lord Jesus, the only lawgiver, to be continued in His Church to the end of the world.
These holy appointments are to be administered only by those who are qualified and called to administer them, according to the commission of Christ.
29. Baptism
Baptism is an ordinance of the New Testament, ordained by Jesus Christ, to be to the person who is baptised - a sign of his fellowship with Christ in His death and resurrection; of his being engrafted into Christ; of remission of sins; and of that person's giving up of himself to God, through Jesus Christ, to live and walk in newness of life.
Those who actually profess repentance towards God, faith in, and obedience to, our Lord Jesus Christ, are the only proper subjects for this ordinance.
The outward element to be used in this ordinance is water, in which the person is to be baptised in the name of the Father, and of the Son, and of the Holy Spirit.
Immersion - the dipping of the person in water - is necessary for the due administration of this ordinance.
30. The Lord's Supper
The Supper of the Lord Jesus was instituted by Him the same night on which He was betrayed to be observed in His churches until the end of the world for the perpetual remembrance, and showing forth of the sacrifice of Himself in His death. It was also instituted by Christ to confirm believers in all the benefits of His death; - for their spiritual nourishment and growth in Him; - for their further engagement in and commitment to all the duties which they owe to Him; - and to be a bond and pledge of their communion with Him and with their fellow believers.
In this ordinance Christ is not offered up to His Father, nor is there any real sacrifice made at all for remission of sin (of the living or the dead). There is only a memorial of that one offering up of Christ by Himself upon the cross once for all, the memorial being accompanied by a spiritual oblation of all possible praise to God for Calvary. Therefore, the popish sacrifice of the mass, as they call it, is most abominable, being injurious to Christ's own sacrifice, which is the only propitiation for all the sins of the elect.
The Lord Jesus has, in this ordinance, appointed His ministers to pray and bless the elements of bread and wine (so setting them apart from a common to a holy use) and to take and break the bread, then to take the cup, and to give both to the communicants, also communicating themselves.
The denial of the cup to the people, the practices of worshipping the elements, lifting them up or carrying them about for adoration, or reserving them for any pretended religious use, are all contrary to the nature of this ordinance, and to the institution of Christ.
The outward elements in this ordinance which are correctly set apart and used as Christ ordained, so closely portray Him as crucified, that they are sometimes truly (but figuratively) referred to in terms of the things they represent, such as the body and blood of Christ. However in substance and nature they still remain truly and only bread and wine as they were before.
The doctrine commonly called transubstantiation, which maintains that a change occurs in the substance of the bread and wine into the substance of Christ's body and blood, when consecrated by a priest or by any other way, is repugnant not only to Scripture but even to common sense and reason. It overthrows the nature of the ordinance, and both has been and is the cause of a host of superstitions and of gross idolatries.
Worthy receivers, outwardly taking the visible elements in this ordinance, also receive them inwardly and spiritually by faith, truly and in fact, but not carnally and corporally, and feed upon Christ crucified, and all the benefits of His death. The body and blood of Christ is not present corporally or carnally but it is spiritually present to the faith of believers in the ordinance, just as the elements are present to their outward senses.
All ignorant and ungodly persons who are unfit to enjoy communion with Christ are equally unworthy of the Lord's Table, and therefore cannot without great sin against Him, take a share in these holy mysteries or be admitted to the Supper while they remain in that condition. Indeed those who receive (the elements) unworthily, are guilty of the body and blood of the Lord, eating and drinking judgement to themselves.
http://www.spurgeon.org/~phil/creeds/bcof.htm#part28