It appears to me that the so-called "Doctrines of Grace" contain a practical contradiction. The T in TULIP states that the reprobate (and even the unregenerate elect) are zealous in their hatred of God. The reprobate completely and totally despise God with their words, thoughts, actions, etc. The P in TULIP states that all of God's elect will be regenerated and will persevere in faith unto death. Now these two points do not seem contradictory in and of themselves, but what of the subject of apostasy? From Biblical texts and our own experience, we come to understand that some people who appear to love God eventually lose interest for one reason or another and fall away from the faith. Jesus even speaks of such people, who accept the gospel with great joy, only to eventually fall back into the world because they get busy and distracted with the cares of daily life.
It is a typical Calvinist response to simply say that those people were never saved to begin with. Fair enough, but if they were never saved, then they were never regenerate, and if they were never regenerate then they must experience vicious hatred towards God according to TULIP's T. So what would compel a reprobate hater of God to go to church, read their Bible, pray fervently, ask God for forgiveness of sins, get baptized, etc. These do not seem to be actions of people who despise God. Why would a reprobate man experience joy upon hearing the gospel, as Jesus plainly stated?
To Calvin's credit, he attempted to plug this hole by coming up with a doctrine called evanescent grace. Roughly speaking, God in his good pleasure, actively causes a deception to fall upon some reprobate men, which gives them a fleeting desire to worship him and follow Christ. However, this false faith is never the 'real deal' and at the appointed time, God removes the illusion and leaves the man in a worse state than he began. This gives God all the more justification to judge the man to death and condemnation.
Understandably, Calvinists do not appear to have endeared themselves to this doctrine. I'd venture to say that many Calvinists have never ever heard of it. But if a Calvinist does not subscribe to evanescent grace, then there must be some other explanation as to what would compel a God-hating reprobate to praise the name of Jesus Christ, even if only for a limited period of time. What explanations, other than evanescent grace, have Calvinists posited to solve this seeming contradiction in their theology?
Our natural, fallen inner disposition is to hate the God of the Bible – the true and living God who created us – and to replace Him with gods (or “concepts of god”) more to our liking. -- http://lakeopc.net/2017/calvinism-101-total-depravity/
Total Depravity means that every sinner is possessed with a nature, inherited from Adam's fall, that is completely hostile toward God. We were all born with a "positive" aversion to God and His authority. By nature, every sinner wants "his own way." Romans 8:7 makes this fact very clear. "The sinful mind is hostile to God. It does not submit to God's law, nor can it do so." -- https://www.monergism.com/doctrine-total-depravity
But a man who is totally depraved can not will to be saved. He hates God and wants nothing to do with Christ's death. So it must not be said that Christ died for all men. -- http://www.prca.org/pamphlets/pamphlet_41.html