OSAS is biblical!
Colossians 3:3-4
King James Version
3 For ye are dead, and your life is hid with Christ in God.
4 When Christ, who is our life, shall appear, then shall ye also appear with him in glory.
Ephesians 2:8-10
King James Version
8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
9 Not of works, lest any man should boast.
10 For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.
Romans 10:9-13
King James Version
9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
11 For the scripture saith, Whosoever believeth on him shall not be ashamed.
12 For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him.
13 For whosoever shall call upon the name of the Lord shall be saved.
Ephesians 2:5-7
King James Version
5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;)
6 And hath raised us up together, and made us sit together in heavenly places in Christ Jesus:
7 That in the ages to come he might shew the exceeding riches of his grace in his kindness toward us through Christ Jesus.
Romans 8:28-39
King James Version
28 And we know that all things work together for good to them that love God, to them who are the called according to his purpose.
29 For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren.
30 Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified.
31 What shall we then say to these things? If God be for us, who can be against us?
32 He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?
33 Who shall lay any thing to the charge of God's elect? It is God that justifieth.
34 Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.
35 Who shall separate us from the love of Christ? shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword?
36 As it is written, For thy sake we are killed all the day long; we are accounted as sheep for the slaughter.
37 Nay, in all these things we are more than conquerors through him that loved us.
38 For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come,
39 Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.
John 10:28-29
King James Version
28 And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
29 My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand.
John 3:36
King James Version
36 He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
Colossians 1:13
Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:
Philippians 1:6
King James Version
6 Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:
Hebrews 10:14
King James Version
14 For by one offering he hath perfected for ever them that are sanctified.
Hebrews 13:5
King James Version
5 Let your conversation be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee.
There are many others as well.
Your verses you cite are all about our experience and receiving the consequences of sin in this life. what you and so many others who falsely believe one can lose their salvation fail in is that you reject the fact the sin does not sned a person to hell! Jesus died for all the sins of the world! So bad deeds do not send one ot hell.
Also you have to conclude that Jesus did not die for all your sins if you can lose your salvation, which is sheer foolishness!
also you forget that when one receives Christ by faith- the old man is killed and the new man is born which is being fashioned into the image of Jesus!
We live in two truths. Positional truth and expriential truth. Positionally we are already seen as perfect, and experientially god is cutting the old habits away and replacing them with new Godly ones and Jesus will complete that good work.
YOu call OSAS a man made theory, well believing one can lose their salvation comes direct from the pit of hell.