Eastern Orthodox and Pentecostal-Charismatic Christianity might appear, at first sight, to occupy opposite poles of Christian life, theology, and worship (especially in terms of the "high church-low church" divide). More recent scholarship, however, has increasingly challenged this binary. The present paper, written from a Catholic perspective, gives an outsider's take on these contemporary discussions. In drawing out converging themes within the theology and spiritual practice, in engaging their actual interrelation historically, and in sharing reflections from the author's own life experience, the paper will propose a certain familiarity between the two. Such an examination not only illuminates underexplored affinities but also contributes to broader ecumenical reflection on diversity, experience, and, ultimately, the work of the Holy Spirit in Christianity today.