In most forms of the Baptist model the convert is baptized as a sign that he or she has already been enlightened and taught by the Spirit. At least the believer should understand who Jesus is, how his death on the cross saves us, and there should be evidence that the Holy Spirit has begun changing the person's character and motivation.
Among Anglicans baptism is used to enrol disciples or learners (see John 4:1, Go Make Learners: A New Model of Discipleship in the Church, Wheaton: Harold Shaw, 1981 (link) ). When disciples begin learning they know very little, as in the case of the twelve apostles. On this view baptism is a sign of enrolment in the school of Christ to begin being taught by the Holy Spirit (e.g. Acts 8:14). This is why all the baptisms recorded in the New Testament are immediate (e.g. Acts 16:34.) Infant baptism then becomes a sign of children being enrolled to begin to enjoy the love of God from their earliest days.
And the parable of the Sower describes what happens after baptism.
The two models also yield different pictures of how the bread and wine of the Lord's table are meant to be effective. In a Baptist model the table is only for born again believers. In an Anglican model the Lord's table is used evangelistically. That means that every Anglican communion service is meant to be the equivalent of a Billy Graham invitation. Instead of coming forward to accept Christ, we say "come and eat with us and the Holy Spirit will reveal Christ to you."