14 What shall we say then? Is there injustice on God’s part? By no means!
15 For he says to Moses, “I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.”
16 So then it depends not on human will or exertion, but on God, who has mercy. – Romans 9:14-16
We so depend on the mercy of God. Mercy is giving compassion or forgiveness to someone you have the power to punish or harm. God Almighty is the Judge of all the earth:
Let the nations be glad and sing for joy, for you judge the peoples with equity and guide the nations upon earth. Selah – Psalm 67:4
We can rejoice in the judgment of God because He will judge with justice and equity. But His wrath will be towards the unrighteous. It is that very wrath of God that those who believe in Christ are saved from:
Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God. – Romans 5:9
Through Christ we receive mercy, forgiveness for our sins and we will not face the wrath of God. Jesus took that wrath upon Himself so that we would not experience it. We have received mercy through Christ not to receive the punishment we deserved. God chooses to give mercy on those who have a heart after Him and seek forgiveness.
45 Then he opened their minds to understand the Scriptures,
46 and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead,
47 and that repentance for the forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. – Luke 24:45-47
His mercy is free to be received by all who repent. But, those who reject the free gift of love in Christ will face the wrath of God. God is sovereign and rules over all things but has chosen to honour man’s free will. If you choose to reject God, choose not to believe the word of God, chiose to reject the calling of the Holy Spirit that leads you to Christ you will face God’s wrath. But, God sent His Son to die for us and take the punishment we deserve. True mercy, taking our punishment for us. His blood shed so the mercy of God could be revealed:
for this is my blood of the covenant, which is poured out for many for the forgiveness of sins. – Matthew 26:28
The mercy of God depends not on our will or our ability but on the work of Jesus Christ who God chose to send to save us:
But we ought always to give thanks to God for you, brothers beloved by the Lord, because God chose you as the firstfruits to be saved, through sanctification by the Spirit and belief in the truth. – 2 Thessalonians 2:13