Anglicans (along with the early Church and most Christian traditions) would reverse this. Baptism is not about what we do for God. It is about what God, through His family, does for us. It is a "rite of adoption" in which we are "reborn" as part of the Church, which is God's family on Earth (BCP pp. 306-308). It is an outward, visible sign of the spiritual reality of being joined with the Church, Christ's body. In short, it is a symbol of how God feels about us: He Loves us and wants us to be His children.
This is a crucial distinction, because if baptism is about our feelings toward God, then we should only do it after we have feelings for Him, that is, after we have chosen to make a mature faith commitment to Christ. Yet, if baptism is about how God feels about us, as Anglicans believe, then God's family should baptize us as soon as possible to make us part of the Body of Christ. Then, within this body, the family of God should raise us up to make our own mature faith commitment in Christ at confirmation.
Much of this comes from how Anglicans understand God's continuing work through Scripture and history. We tend to stress the continuity of the Old Testament with the New Testament. We believe that the teachings of the Jewish prophets and the temple sacrifices before Christ pointed toward His life and sacrifice, and shared in His life and sacrifice. So also we believe the teachings of the Christian apostles and the sacrament of Communion point backward to, and share in, Christ's life and sacrifice.
In the same way, we see that people were made part of the Old Covenant as infants by the act of circumcision (Gen 17:7-14; Acts 7:8). Circumcision was not primarily about how the Jews felt about God, but about how God felt about the Jews (although mature Jews tended to take very seriously their circumcision, just as mature Christians take very seriously their Baptism: Rom 3:1-2). Circumcision was done to bring the children under the promises and protection of the covenant family of God (Rom 4:9-11; Gen 17:14). It was then the job of the family to raise those children to have a mature faith as dedicated disciples of the one true God (Deu 4:9-10, 6:4-25, 11:19).
Now, we believe that baptism is to the Church as circumcision was to Israel. In fact, the New Testament draws an explicit connection between circumcision of the Old Covenant and baptism of the New Covenant (Col 2:11-12). But baptism differs from circumcision in one respect: circumcision was for male children only, but baptism is for males and females (Gal 3:27-29). Perhaps this is because the Old Covenant was limited to one ethnic people and focused on one location, the Temple, while the New Covenant is for every tribe and tongue and not focused on any single location (Deu 12:4-11; 1Ki 9:3; John 4:19-24). The universal nature of the New Covenant is represented in the universal application of baptism.
Yet, just like under the Old Covenant, the parents and extended family of the Church have the duty to raise up the children of the Covenant to have a mature faith as dedicated disciples of Christ when they come of age (Eph 6:4; 1Ti 3:4-5). This explains many things in our baptismal service. First, you will notice that we have parents and God-parents involved in baptism, and it is the job of both to ensure that the child is raised up to believe in Christ (BCP p. 301-303). But not only is it their job.
It is also the job of the entire congregation, and that that is why everyone present re-affirms their own baptismal covenant and promises to raise the child according to that covenant (BCP p. 303-306). Once the child is of age, and can make an adult, informed, choice to believe in Jesus, then they come up in front of the congregation and promise, for themselves, to follow Christ (Deu 29:12-15; 1Ti 6:12-14; Rom 10:9-10). This adult faith decision is called "Confirmation" (BCP pp. 413-419).
Non-infant baptism Churches do the same thing, using different rituals. These Churches "dedicate" the child to the Lord when they are infants, and promise, along with the rest of the Church, to raise the child to follow Jesus. When the child gets old enough, they are expected to receive Christ, make a public confession of faith, and then get baptized as a sign of that commitment. They replace baptism with dedication, and replace confirmation with baptism. While I am sure the Lord accepts this ordering, the more Biblical order seems to be the way Anglicans and most other Christians do it: infant baptism, then adult confirmation.
This ordering of things comes from the very first Christian sermon ever preached in Acts 2. In it, St. Peter is speaking to Jews who had been circumcising their children for over a millennium. These people were hard-wired to include their children in God's Covenant by means of a physical ritual. To these people, Peter says: "Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins... the promise is for you and for your children and for all who are far off..." (Acts 2:38-39). Notice that the promise is "for you" (those adults who could hear and understand the message) and for "your children" (the Greek word here is used for small children and infants). It is fairly clear that he meant that baptism was for adult converts AND their children.
If St. Peter had meant "only adult believers can be baptized", then he would have had to specially explain that that to the crowd, who would have expected to include their children under the New Covenant rite of Baptism just as they were included in circumcision. Yet, we find no such special instructions from Peter. In fact, we find the opposite. We find that the apostles baptized entire households on a regular basis (see Acts 16:15-33, 18:8; 1Co 1:16, 7:14). In ancient times, someone's "household" or "family" included all babies, children, wives, and servants in the house. Yet, not just any infants are baptized, but only those who's parents are confessing members of God's Family. If a person comes from a non-Christian home, then they are gladly baptized as adults, just like the apostles did for countless adult converts (see Mat 28:19-20; John 3:22-23, 4:1; Acts 2:41, 8:12-13, 18:8).
A last misconception about infant baptism is that Anglicans baptize infants as some type of "get out of hell free" ritual, as if personal faith were not necessary to enter salvation. Scripture clearly states that it is not external washing that cleanses sin, but personal faith accepting the gift of a clean conscience before God (1Pe 3:20-21). We are saved by grace through faith, not as the result of works, even the work of Baptism (Eph 2:8-9).
In the Creed, we state that baptism is "FOR the forgiveness of sins", just as St. Peter said in Acts 2:38. Some think this means that baptism causes the forgiveness of sins, but that doesn't mesh with the rest of Scripture. When I say that I got presents FOR my birthday, it does not mean that my presents caused my birthday (as if presents could make me exist). It means that I got presents BECAUSE it was my birthday. In the same way, both the Bible and the Creed mean that we are baptized into God's family because we are forgiven by Him (NOT forgiven because we are baptized).
Baptism does not bring automatic forgiveness or automatic salvation. Instead, because of God's forgiveness, he gives us baptism to join us to His Covenant community, the Church (1Co 12:13; Eph 4:1-5). Baptism is an adoption ceremony into God's earthly family (Gal 3:27-29). By baptism, we are joined to Christ's death and resurrection through His body, the Church (Rom 6:4-5). So long as children are too young to exercise mature faith on their own, their parents' faith makes them "holy" to God (1Co 7:14). Although all people are sinners, God does not hold people, accountable for sin they do not understand (Rom 7:7-11; John 9:41; 2Sa. 12:21-23; Isa 7:16). Thus, those who are unable to believe consciously, such as children, are saved through Christ (Mark 10:13-16). Yet, when they get old enough, they must choose Christ for themselves (Rom 10:9-10; John 1:12-13, 3:16-21). Neither baptism nor circumcision nor any other ritual can make a person right with God if they will not have faith in Christ (Rom 2:25-29; John 3:36).
So, in summary, we do not baptize infants, or adult converts, as a magical act of salvation. We baptize to bring people into the family of God, so that they are explicitly under God's promises and protection for His Covenant community. In the case of infants, it is required that this family help them grow to a mature faith in Christ, and that the children confirm their own faith when they come of age. We baptize infants because this seems to be the clear Biblical pattern given for children of believing parents.