@KingJ - IMO your arguments are misrepresenting what I believe (you might call me an anti-OSAS person). Here is my response to your points:
Jude 1:20-24
20But you, beloved, building yourselves up in your most holy faith and praying in the Holy Spirit,
21keep yourselves in the love of God, waiting for the mercy of our Lord Jesus Christ that leads to eternal life.
22And have mercy on those who doubt;
23save others by snatching them out of the fire; to others show mercy with fear, hating even the garment
g stained by the flesh.
24Now to him who is able to keep you from stumbling and to present you blameless before the presence of his glory with great joy,
25to the only God, our Savior, through Jesus Christ our Lord, be glory, majesty, dominion, and authority, before all time
h and now and forever. Amen.
We see that it is only by the grace of God that we can be presented blameless before Him. But we are told to keep ourselves in the love of God - not a hard task but a walk of faith. We reach out in compassion to those who are in danger of backsliding.
God does not help us escape temptation.
1 Corinthians 10:12-14
12Therefore let anyone who thinks that he stands take heed lest he fall.
13No temptation has overtaken you that is not common to man. God is faithful, and he will not let you be tempted beyond your ability, but with the temptation he will also provide the way of escape, that you may be able to endure it.
14Therefore, my beloved, flee from idolatry.
We see here that we are to take heed lest we fall, yet realize that there is a way of escape when we are tempted. We are to flee via this way of escape. If your house was on fire, and you were trapped, and a fireman blasted a hole in the wall for you to escape, and you refused to leave, would you say that the fireman did not help you escape unless he came in and dragged you out? God richly blesses us and provides for us. We must choose to take action.
God sets us up for a fall.
No, see the scriptures above.
2 Peter 1:3-11
3His divine power has granted to us all things that pertain to life and godliness, through the knowledge of him who called us to
c his own glory and excellence,
d 4by which he has granted to us his precious and very great promises, so that through them you may become partakers of the divine nature, having escaped from the corruption that is in the world because of sinful desire.
5For this very reason, make every effort to supplement your faith with virtue,
e and virtue with knowledge,
6and knowledge with self-control, and self-control with steadfastness, and steadfastness with godliness,
7and godliness with brotherly affection, and brotherly affection with love.
8For if these qualities
f are yours and are increasing, they keep you from being ineffective or unfruitful in the knowledge of our Lord Jesus Christ.
9For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins.
10Therefore, brothers,
g be all the more diligent to confirm your calling and election, for if you practice these qualities you will never fall.
11For in this way there will be richly provided for you an entrance into the eternal kingdom of our Lord and Savior Jesus Christ.
Everyone is given a choice to accept the plan of salvation. Everyone who becomes a child of God is showered with ample grace and mercy to fight the good fight. As we grow in grace and knowledge we become fruitful and gain steadfastness.
People are not truly saved.
Yes we are truly saved, yet we still have free will. Being born again and becoming a child of God does not absolve you of the will to turn away from Him.
We must keep ourselves saved.
We do not keep ourselves saved, but use the armor God provides us, utilize the grace He showers on us daily to follow Him, and return our love to Him as He has loved us.
Why then be in Christianity. All religions are good.
Jesus is the only way.
John 14:5-6
5Thomas said to him, “Lord, we do not know where you are going. How can we know the way?”
6Jesus said to him, “I am the way, and the truth, and the life. No one comes to the Father except through me.
Anti OSAS teaching undermines the cross.
I would actually say it does the opposite - it magnifies the grace of God and His love and care for His children, who He richly blesses daily with grace and mercy, that we may walk in this life and "keep ourselves unspotted from the world". James 1:27 Even tho we have an enemy who is "seeking whom he may devour", 1 Peter 5:8-9 he has no power over us for we can easily resist him in the faith, as we are given instructions to do.