Calvinism has an excellent comprehension of what GRACE means, and the other systematic philosophies do not understand GRACE properly at all. We are only saved by His grace.
People are born again of the Spirit as a first step in their salvation, otherwise they can not see, perceive the kingdom of God
People are born again according to the will of God, not the will of a man
All those not born again have ENMITY against God and Christ
All people not born again resist the Holy Spirit.
Christ chooses as an exercise of HIS WILL who knows God and Christ
The reason God saves some by His grace is His great love He has for them only and not the others
The reason we love God is because He loved us first and sent His Son to be the propitiation for our sins, ours being only the foreknown elect.
We are elect according to foreknowledge
Only 'the frozen chosen', will believe, all the rest are not chosen for salvation, God knew His elect from before time began as His people, so that number can not be modified, added or subtracted from, it is frozen in time.
Honestly the depravity of men and their spiritual condition of loving SATAN and the lusts of the flesh show they can not do the right thing with God and be obedient to God's command to repent and believe in Christ. If God did not predestine people, no one would follow Christ.
When you say differently, then it is not grace that saves but a work of your flesh, your will and not the work of God.
There us overwhelming scriptural proof for all the above. People generally presume way to much about their own ability to believe.
When God predestines people to believe, it makes the promise sure to all the seed. And the elect must be saved.
Romans 4:16
Therefore
it is of faith that
it might be according to grace, so that the promise might be sure to all the seed, not only to those who are of the law, but also to those who are of the faith of Abraham, who is the father of us all
2 Timothy 2:10
Therefore I endure all things for the sake of the elect, that they also may obtain the salvation which is in Christ Jesus with eternal glory.
the elect must and will be saved and only the foreknown elect. The elect being born in a fallen condition have to go through the salvation experience. They are born elect, not born saved.