How do you find this Arminian to begin with? It's like asking: "Is somebody who is a Calvinist saved?" Who are you talking about? I'm serious, who specifically is being referred to when you ask about a person's salvation.
It's far too simple to broad brush an entire population of people and call them Arminians and say: such are lost or such are saved. This is why we get into large arguments that, in some cases, are pointless. We have some, on the one hand, that merely want to affirm that "...there are Arminians who are saved..." while there are others who want to affirm "...an Arminian can't be saved...."
I always want to know who, specifically, are we talking about because Christians are the ones that are saved. I prefer to think of people in the Church, baptized into Christ, as Christians. They are in the visible Church by varying levels of good or bad confession but have been baptized nevertheless. While in the Church, Pastors have a responsibility to preach to and discipline them.
Thus, I want to separate the individual that I meet in a Church who has heard the Word preached (well or poorly) from the good or bad doctrine that is taught by those who are charged with rightly divining the Word of Truth. I would say, then, that we have men and women who are Christians visibly by baptism who are under the influence of Arminian or Reformed or Lutheran, etc. doctrine. I sometimes refer to myself as Reformed but primarily I call myself a Christian with a Reformed Confession.
I HATE Arminian doctrine. I don't know how much more clearly I can state it. The doctrine undermines the Gospel at nearly every turn and focuses attention away from the grace that saves and points it inward to the will of man and even a form of works righteousness. I pity, with tears sometimes, Christians who are impoverished and starved to death under this doctrine. Some of them are Christians externally only because their blind guides have seen to it that they never hear Christ crucified for the sins of those who believe upon Him but hear, instead, about how Christ makes you a happy person or how He is your co-pilot.
Even those that received a garbled message that Christ died for sinners don't get the Gospel week in and week out but hear too much about how they need to imitate Christ and do things. They aren't told of their place in Christ or the assurance of their salvation and so they come to Church guilt-ridden over their sin and leave guilt-ridden because they think the Gospel is for converts but then the rest is up to them.
I HATE, HATE, HATE Altar Calls. I think it's as Gospel denying an ordinance as Penance. The idea of re-dedication is a constant "clean up your act" message. Many Churches practice re-baptisms as well because men and women are constantly paralyzed by thinking that it is the strength of their faith that saves them and not their simple trust in the death and resurrection of Christ. They thus are assaulted on every side by sin that overcomes and then Satan whispers in their ear and says: "You didn't really have faith enough that saves or you wouldn't have committed this sin." It's why so many atheists come out of these Gospel-denying Churches that place the tenor of faith on the conversion experience and the focus on the self instead of the Cross.
And so my answer to your question is this: don't worry about who's in and who's out. Don't worry about who's saved and who's not saved as a crowd. There are lost men and women in OPC Churches and there are saved men and women in Assembly of God Churches. But that distinction doesn't mean that it is immaterial what the two bodies teach. I'm not saying: "Who cares what they teach." People are much less likely to hear the Gospel in an AOG that has blocked the Word at every turn with their man-centered doctrine while the OPC is much less likely to have those snares.
But men are sinners and even a blessed Confession like the WCF is no guarantee that a man is saved.
Thus, when it is up to you to teach men and women in the Church, don't play duck, duck, goose and try to figure out who are the saved and who are the lost. Teach the Word of God faithfully. Teach it like human souls depend upon it. Present Christ and His work as something outside of them. Tear down the walls that keep men from the clear presentation of the Gospel.
And watch the power of the Word, working together with the Spirit, transform hearts and minds.
