I spent my first 44 years in the Christian and Missionary Alliance, a split-off from the Presbyterian Church in the 1890's under the leadership of A.B.Simpson who had a vision for missions. When I became Orthodox, I was required to denounce some of the heretical ideas of my former belief... namely predestination. It's right there in the conversion service. Check out the service book by Isabel Hapgood under the section for the bringing of those from Calvinist backgrounds into the Church. While "some" Fathers of the Church may have made enigmatic statements regarding predestination, that really means nothing. The Fathers were not always in agreement with one another of a number of issues. We must come to terms with the service for converting from a Protestant background to the Orthodox Church and that will most definitely require a denouncing of such former heretical ideas as predestination.