Rev. Robert J. Gaestel describes CGS:

The Catechesis of the Good Shepherd is [an approach to] Christian education that presents the most important realities of the Christian faith to the youngest members of the Church. This manner of Christian [formation] assumes that young children have religious potential. That is, God having already made himself present to them in their deepest being, they are capable of developing both a conscious and intimate relationship with God. They only need the guidance and vocabulary to enable them to become aware of their relationship with God and give expression to it.

This is done by means of two things, a prepared environment, and a trained catechist whose sources are Scripture and Liturgy. The prepared environment contains materials that are models of things used in the Church's worship such as altar, Eucharist, baptism, liturgical colors, etc. The environment also contains materials relating to the proclamation of the faith such as parables, prophecies, geography of Israel, and the life of Christ. These are manipulatives [that aid the young child, who cannot read, in their ongoing meditation on various themes.]  

The trained catechist makes presentations to the child, using the materials [more as an invitation to the child to continue the meditation after the formal presentation has been given.]  These presentations are chosen to convey the essentials of the faith in a manner appropriate to the child's development. The child is then invited to internalize and respond to the presentation by working with the materials themselves. The catechist does not give answers or impart information. The catechist presents the reality, and asks questions. The catechist assists in the child's own discovery of the meaning. The motto of CGS is "Help me fall in love with God by myself."