Evangelization is about encountering Jesus Christ. And so is catechesis. Church teaching is truth. And Jesus Christ is the Truth. When we share the faith, therefore, we share Christ. So whatever the topic might be, the goal is for students to connect it to their living, personal relationship with Jesus. If we can't understand how purgatory, for example, fits into our relationship with Christ, we'll be hard-pressed to truly understand it's importance. The same goes for any topic: the sacraments, prayer, vocation, sin, death, virtue, grace, social justice, heaven, hell, or any other tenant of faith. If it isn't understood and taught in relation to the Person of Jesus Christ, it's being "suffocated" and, most likely, we'll never encounter him through the teaching.
"At the heart of catechesis we find, in essence, a Person, the Person of Jesus of Nazareth, the only Son from the Father…who suffered and died for us and who now, after rising, is living forever…Catechesis aims at putting “people…in communion…with Jesus Christ: only he can lead us to the love of the Father in the Spirit and make us share in the life of the Holy Trinity (CCC 426). In catechesis “Christ, the Incarnate Word and Son of God,…is taught – everything else is taught with reference to him (CCC 427).
As we learn to see these connections and to encounter Christ in the doctrines of the Church, not only does our own faith grow but so too does the faith of those around us as we share it.