Calvinists are wrong to think God first designed sinners incapable of turning from sin and then burning them in hell in wrath for refusing to turn from their sin.See if Christ didn't die for us to deliver us from unbelief, then it would be no hope and no faith in Christ since by nature all of us as sinners are shut up unto unbelief Rom 11:32
32 For God hath concluded them all in unbelief, that he might have mercy upon all.
For God hath shut up all unto disobedience, that he might have mercy upon all. AV
For God hath shut up together all in unbelief, in order that he might shew mercy to all. Darby
It takes the sovereign mercy of God to come out of unbelief 1 Tim 1:13
13 Who was before a blasphemer, and a persecutor, and injurious: but I obtained mercy, because I did it ignorantly in unbelief.
He obtained Mercy from the Lord
1 Cor 7:25
Now concerning virgins I have no commandment of the Lord: yet I give my judgment, as one that hath obtained mercy of the Lord to be faithful.