You shouldn't be amazed at the lies people believe. When God sends strong delusion on people, how can they not believe contradictory and false things? Don't look to the ability of man to see the truth, but look to the sovereignty and power of God who grants or denies men sight.
“And for this cause God shall send them strong delusion, that they should believe a lie: That they all might be damned who believed not the truth, but had pleasure in unrighteousness” (2 Thessalonians 2:11-12 KJV).
Romans 11:5-8 EMTV
(5) Even so then, at this present time also there is a remnant according to the election of grace.
(6) And if by grace, it is no longer of works; otherwise grace is no longer grace. But if it is of works, it is no longer grace; otherwise work is no longer work.
(7) What then? Israel has not obtained what it seeks; but the elect have obtained it, and the rest were blinded.
(8) Just as it is written: “God has given them a spirit of stupor, eyes that they should not see, and ears that they should not hear, to this very day.”
Haven't you been in darkness during your lifetime, believing egregious lies, under the wrath of God? And if you were delivered from this awful state - how? By your will and intelligence, or by the grace of God? His mercy must reach into hell, or none of us would ever be saved!
As for Luke 16:27-30 and what you perceive it says about the mercy of God, that isn't a spring of pure water. Read The Rich Man and Lazarus A Pagan Parable
Regarding Calvinism, we need to qualify a technical point from our earlier letter. We asked Martin VanPopta, a brother in the Lord raised in the Reformed Church, about their doctrine: “Most of the Calvinists are 'certain' of their salvation. These would be the Christian, Canadian, Free, and First Reformed denominations. This is why they are so smug. They are the chosen ones and are afforded this surety of their salvation by virtue of the sacraments of infant baptism and holy supper. Of course, they won't admit that the sacraments are necessarily for or the cause of their salvation, but Calvin himself would.
“It is the Netherlands Reformed Church that preaches the uncertainty of salvation. These would be the strict and particular, black stocking and weird hat wearing ones, that built the big brick church just east of Victory. They preach that you never really know what is going to happen.
“I don't know if your letter needs correction as none of the Calvinist truly have any hope of salvation, but I thought I would put you through Catechism class for a minute ”
This last point of Martin's agrees with what you say about the Calvinist god. Who can truly trust and be secure with such a perverse and hateful god or understand its consort, false religion?
Proverbs 5:1-6 MKJV
(1) My son, listen to my wisdom; bow your ear to my understanding;
(2) in order to keep discretion, that your lips may keep knowledge.
(3) For the lips of a strange woman drip honey, and her palate is smoother than oil;
(4) but afterward she is as bitter as wormwood, sharp as a two-edged sword.
(5) Her feet go down to death; her steps take hold on hell,
(6) lest you should meditate on the path of life, her tracks are movable; you cannot know them.