Q —Why can’t I pray directly to a saint, but just for the intercession of saints?
A — We cannot pray “directly” to a saint because, strictly speaking, saints do not exist on their own, just as the baptized do not exist on their own but only as embodied in Christ,  only “in Christ” to use the term preferred by St. Paul. When, therefore, we pray to the saints, we pray to the saints “in Christ.” Intercession has to do with our communion in and with the communion of the saints, in Christ, and never apart from him.