The Alliance (Becoming Beka Series, Book 2) by Sarah Anne Sumpolec

Beka heads back to school with a newfound faith, but that faith is tested sooner than she expected. As she spends time with the eclectic theater group, she is pulled further into her friendship with Gretchen, who becomes fascinated with the occult and convinces Beka there is no harm in the tarot cards, crystals, and spells that their group of friends is dabbling in. Beka also struggles in her growing relationship with Mark, who is pressuring her to spend time with him behind her father's back. In the midst of all these shifting alliances, Beka must decide where her true loyalties lie.