Wherein do the sacraments of baptism and the Lord's supper differ?

The sacraments of baptism and the Lord’s supper differ, in that baptism is to be administered but once, with water, to be a sign and seal of our regeneration and ingrafting into Christ,[1] and that even to infants;[2] whereas the Lord’s supper is to be administered often, in the elements of bread and wine, to represent and exhibit Christ as spiritual nourishment to the soul,[3] and to confirm our continuance and growth in him,[4] and that only to such as are of years and ability to examine themselves.[5] 

1. Matt. 3:11

   I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire.

   Titus 3:5

   …he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit….

   Gal. 3:27

   For as many of you as were baptized into Christ have put on Christ….

2. Gen. 17:7, 9

    And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you.      

   And God said to Abraham, “As for you, you shall keep my covenant, you and your offspring after you throughout their generations.

   Acts 2:38-39

   And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit. 39 For the promise is for you and for your children and for all who are far off, everyone whom the Lord our God calls to himself.”

   I Cor. 7:14

   For the unbelieving husband is made holy because of his wife, and the unbelieving wife is made holy because of her husband. Otherwise your children would be unclean, but as it is, they are holy.

3. I Cor. 11:23-26

   For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, 24 and when he had given thanks, he broke it, and said, “This is my body which is for  you. Do this in remembrance of me.”  25 In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” 26 For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until he comes.

4. I Cor. 10:16

   The cup of blessing that we bless, is it not a participation in the blood of Christ? The bread that we break, is it not a participation in the body of Christ?

5. I Cor. 11:28-29

     Let a person examine himself, then, and so eat of the bread and drink of the cup. 29 For anyone who eats and drinks without discerning the body eats and drinks judgment on himself.

Question 177, Westminster Larger Catechism