Do most Advent Christians hold to eternal security? Is there a predominant view among Advent Christian Church members (a.k.a First-day Adventists) regarding the doctrine of Perseverance of the Saints, sometimes called "eternal security"?
I know this is late but I will try to answer.  No, there is no predominant belief among Advent Christian Churches as to perseverance of the saints.  This is strange because even though the majority of the pastors attended the same college, taught by the same professors, it never really filtered to the churches they served right out of college.  Now that the college has been gone since 1986, the next generation of church members now under the discipleship of those pastors from their college do believe it, it's probably most likely those congregations do believe it now.

Also, it is probably more predominant in the NE than in the SE of the country.