Good Morning!
The Bible refutes OSAS very clearly;
Nay, Once A Son Always a Son......
Unlimited number of times we can receive forgiveness...
Justification is by His blood is one time.
Forgiveness:
Matt 18:21 Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times?
Matt 18:22 Jesus saith unto him, I say not unto thee,
Until seven times: but, Until seventy times seven.
Our Lord and Savior would not give a commandment that HE WOULD NOT DO HIMSELF...but He does
Again , 1 John 1:9
why does scripture warn us about backsliding?
Sliding back to former things, of the world
1John 2:15 Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him.
1John 2:16 For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.
1John 2:17 And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever.
Why does scripture say...maintain (Righteousness) until the end?
The Christ maintains HIS Righteousness in those who are His
For Christ is the end of the law [it leads to Him and its purpose is fulfilled in Him], for [granting] righteousness to everyone who believes [in Him as Savior].
John 15:5 I am the vine, ye are the branches: He that abideth in me, and I in him, the same bringeth forth much fruit:
for without me ye can do nothing.
Acts 17:28
For in him we live, and move, and have our being; as certain also of your own poets have said, For we are also his offspring.
Why does scripture intent show God/Christ/Holy spirit cannot reside where sin is present?
We are all fallen, by nature, but yet He made promises to those who are His;
John 14:23 Jesus answered and said unto him, If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him.
God Bless!