Eternal security, the teaching that once a person puts his faith in Christ he cannot be lost (which is considered a "Calvinist" view), has long been a part of the EFCA fellowship. But conditional security (which is considered an "Arminian" view), the teaching that a believer is secure from condemnation as long as he keeps on believing in Christ, has just as long a history.
These two teachings go all the way back to the founding days of the fellowship, so much so that former president A.T. Olson refers to them in his book The Significance of Silence. The EFCA decided at that time not to draw a line on that doctrine, and that's still the policy today.
Though local pastors and congregations usually do have an opinion on the subject, and an individual church's pulpit will reflect that opinion, the EFCA association on the national scale doesn't take a stand. A man can become ordained to the preaching ministry in the EFCA and hold either view. A church can lean to either doctrine, and still be EFCA member churches in good standing.
This policy sounds a bit loose, until you realize we have a clear statement of faith, which speaks to the essential truths of salvation as well as the other foundational truths of Christianity. We also have a book available, Evangelical Convictions, that elaborates on the statement of faith.
But there are limits. Where do the limits lie? In a personal conversation I had several years back with an assistant district superintendent, he told me there were extremes at either end of the Calvinist-Arminian spectrum which would fall off the edge of acceptability, as far as what we could or would tolerate. Here are some examples:
On a hyper-Calvinist extreme, we stop any teaching that treats the spiritual life as operating on passive auto-pilot, as if the exhortations and warnings of the New Testament don't matter and are just for show. We would stop any teaching that excused, condoned, or made light of sin in any way. Our statement of faith also explicitly forbids any teaching that breaks the connection between positional justification in Christ and practical holiness (Statement of Faith 8, .https://www.efca.org/resources/document/efca-statement-faith).
The severe error that sometimes happens on the Calvinist side is called antinomianism. Here is a good, short article about that: https://www.gotquestions.org/antinomianism.html
On the hyper-Arminian side, we stop teaching that insinuates good works into why and how someone is justified of their sins. This severe error is usually done by blurring initial saving faith in Christ with all the other ways a growing faith is expressed throughout life, like full dedication, cross-bearing, or Jesus' other teachings about discipleship.
Here is a good quote from an historic catechism called the Larger Catechism that illustrates how not to blur faith with its fruits:
Question 73: How does faith justify a sinner in the sight of God?
Answer: Faith justifies a sinner in the sight of God, not because of those other graces which do always accompany it, or of good works that are the fruits of it, nor as if the grace of faith, or any act thereof, were imputed to him for his justification; but only as it is an instrument by which he receives and applies Christ and his righteousness.
This catechism names three ways faith does not justify us of our sins:
(1) not by all the other gracious operations of the Holy Spirit which he does to draw a sinner to Christ;
(2) not by the good works that result from faith; and
(3) not as if faith itself is the righteousness that saves.
The hyper-Arminian error is called legalism. Here is a good, short article about it: https://www.gotquestions.org/Bible-Christian-legalism.html
Antinomianism is the ditch on the left-hand side of the road. It's a poison that destroys a church by attacking holiness. The idea that a person could have exercised saving faith in Christ but remain as sinful as they ever were is a devilish doctrine. The idea that grace means it's OK to sin is abominable. God's curse is upon such teaching. Christ called it "Nicolaitanism", in the letters of Revelation, and said He hated it.
But the ditch on the right-hand side of the road is legalism. Introducing any good works -- the Ten Commandments, Christ's demands of discipleship, Romans 12:1 -- into justifying faith as a co-condition for justification is Phariseeism.
Good works are a fruit and proof of faith (James 2), not co-conditions for justification. Paul absolutely condemns legalism in Galatians 1:6-8. God's curse is upon it as well.
Antinomianism and legalism are equally bad, and I fight both equally. However, I have met Arminians who confine the possibility of falling-away to a conscious abandonment of Christ -- not just any sin a Christian might commit, but specifically that sin. My former church history professor was of this opinion (he was ordained a Free Will Baptist preacher).
Even though I didn't agree with his view on security, I could see it hypothetically -- saved by full conscious faith in Christ, lost by full conscious denouncing of Christ. That was very different from a Methodist woman I knew who claimed her uncle became eternally lost because he cheated on his wife. As bad as it is to cheat on your wife, her thinking about salvation was completely works-centered.
We will seek to walk in harmony with Scripture, follow our EFCA statement of faith, and take care not drop into either of the two heretical ditches. If we have unknowingly drifted into either of the two ditches, we must get ourselves up and out of them!