Here’s how I discern that some OSAS’ers do not study too well.
If I were a OSAS’er, I would have came back with this scripture to defend myself:
2 Thessalonians 2:13-14
[13] But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth: [14] Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ.
So I will concede that OSAS has a valid aspect to it.
But we ourselves are not in possession of who posses it, only God in heaven knows who will endure to the end.
In the meantime we should walk like this scripture says:
Philippians 3:11-14
[11] If by any means I might attain unto the resurrection of the dead. [12] Not as though I had already attained, either were already perfect: but I follow after, if that I may apprehend that for which also I am apprehended of Christ Jesus. [13] Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, [14] I press toward the mark for the prize of the high calling of God in Christ Jesus.