Also. OSAS can mean that you remain saved no matter what you do, even lapsing into unbelief. But it can also mean that with the help of the Holy Spirit you will persevere and live out a Christian life. In other words a Christian life is required, but inevitable for one truly saved. So it might look different. In other words, the Reformed might say you are saved from apostacy, while a pure OSAS free grace Baptist would say you would remained saved in spite of apostacy.
Disagreement with eternal security can mean different things also. It can mean that if certain additional works or sacraments are not done you will not be saved and justification is not a sure thing until judgment day. It can mean that doing certain serious sins can disqualify you and put you in a lost condition. Or it can mean that sin can be repented of and confessed, and only willful and deliberate falling away or apostacy will result in a loss of salvation, (and this with the understanding that such a scenario may be hypothetical).
Salvation is a BIRTH. It is a birth into the family of God. It is a one time and forever occurrence. It is not a separation of the present family because one retains his body from that first family. That body is a source of a battle for the remainder of the life of the believer. Jesus said of this about this struggle all believers face and Paul tells us something about it here..
Ga 5:17 For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would.
The flesh has not been redeemed, nor can it be. it must be changed and we as born again Christians, the church age saints who are "in Christ and Christ in them and who are one with Christ are promised we will have a new glorified body like unto the body of our Lord Jesus Christ. This is our blessed hope. This will be a body whereby we can inhabit the heavenlies'.
We have an intercessor seated at the right hand of the Father who has justified us and has given us the gift of eternal life, and Jesus Christ can and does petition for forgiveness of every sin a Christian commits because his blood is the payment for sin..
A man who preaches a works salvation after all Jesus Christ has done for us is suspect as to whether he has ever been saved. I did not say that, it is stated here;
Ga 1:6 ¶ I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel:
7 Which is not another; but there be some that trouble you, and would pervert the gospel of Christ.
8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
9 As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.
Grace is a gift of salvation and works is another gospel and is some form of self effort of keeping the law and earning it. It is a very serious error. Being accursed is no fun thing.
Php 3:17 ¶ Brethren, be followers together of me, and mark them which walk so as ye have us for an ensample.
18 (For many walk, of whom I have told you often, and now tell you even weeping, that they are]the enemies of the cross of Christ:
19 Whose end is destruction, whose God is their belly, and whose glory is in their shame, who mind earthly things).
20 For our conversation is in heaven; from whence also we look for the Saviour, the Lord Jesus Christ:
21
Who shall change our vile body, that it may be fashioned like unto his glorious body, according to the working whereby he is able even to subdue all things unto himself.
We will not be able to sin in a glorified body and there will not be a struggle.