Calvinists believe in Irresistible Grace which is a specific Grace God works in those purposed for salvation from before the world began. We believe that God appointed a time, within the timeline of creation, where the Holy Spirit would regenerate those purposed individuals such that they no longer perceive Christ crucified as foolishness but perceive him as the irresistible wisdom and power of God for salvation. Because of God’s gracious gift of change in perception Christ has become to us the Power that motivates us to endure to the end so as to be saved and inherit eternal life. Those purposed for salvation are acting out what God is working in them. This is how God saves his purposed people from beginning to end.
The LORD has made everything for its purpose,
even the wicked for the day of trouble.
And when the Gentiles heard this, they began rejoicing and glorifying the word of the Lord, and as many as were appointed to eternal life believed.
1 Cor 1:30
And because of him you are in Christ Jesus, who became to us wisdom from God, righteousness and sanctification and redemption,
“but we preach Christ crucified, a stumbling block to Jews and folly to Gentiles, but to those who are called,… Christ the power of God and the wisdom of God.” (1Co 1:23-24)
“For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God.” (1Co 1:18)
“work out your own salvation with fear and trembling. For it is God which worketh in you both to will and to do of his good pleasure.” (Php 2:12-13)
Thats why they always take the 5th!