Now when they heard this, they were cut to the heart, and said to Peter and the rest of the apostles, "Men and brethren, what shall we do?" Then Peter said to them, "Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit. For the promise is to you and to your children, and to all who are afar off, as many as the Lord our God will call." And with many other words he testified and exhorted them, saying, "Be saved from this perverse generation."
Acts 2:37-40

When the believers in the crowd asked Peter “what shall we do?” his reply was “repent…and be baptized.” Why did he say “let every one of you be baptized in the name of Jesus Christ for the remission of sins.”? Here are a few answers found in good commentaries:

There is nothing in baptism itself that can wash away sin. That can be done only by the pardoning mercy of God through the atonement of Christ. But baptism is expressive of a willingness to be pardoned in that way, and is a solemn declaration of our conviction that there is no other way of remission. He who comes to be baptized, comes with a professed conviction that he is a sinner; that there is no other way of mercy but in the gospel, and with a professed willingness to comply with the terms of salvation, and to receive it as it is offered through Jesus Christ.

…not that forgiveness of sin could be procured either by repentance, or by baptism; for this is only obtained by the blood of Christ; but the apostle advises these awakened, sensible, repenting, and believing souls, to submit to baptism, that by it their faith might be led to Christ, who suffered and died for their sins, who left them buried in his grave, and who rose again for their justification from them; all which is, in a most lively manner, represented in the ordinance of baptism by immersion.

As the cup in the Lord's Supper is the New Testament in the blood of Christ for the remission of sins, so baptism is in the name of Christ for the remission of sins. (I might add, “Why do so many neglect both sacraments that are commanded of believers—usually because they are not obeying the command to be in a church where the sacraments are administered?” And again, “Why do so many receive the Lord’s Supper while refusing baptism?”)

Baptism is the visible sign and seal of remission of sins that is in Christ alone. Let us receive both baptism and the Lord’s Supper, rejoicing in Who they point us to.