9 Yet for my own sake and for the honor of my name,
I will hold back my anger and not wipe you out.
10 I have refined you, but not as silver is refined.
Rather, I have refined you in the furnace of suffering.
11 I will rescue you for my sake—
yes, for my own sake!
I will not let my reputation be tarnished,
and I will not share my glory with idols! (Isaiah 48:9-11, New Living Translation)
Christianity must be true, because only God would save sinners. God proves that he is God by his grace to sinners.
The grace of God is not an afterthought. His grace is not Plan B in view of our failures. Grace is the very nature of God. When Moses prayed, "Show me your glory," God answered, "I will make all my goodness pass before you" (Exodus 33:18,19).
Does it seem obvious to us the God would judge sinners?
Does it seem obvious that God would welcome sinners into the fiery love of the Trinitarian Godhead?
But God is out to prove that he is God not by nuking us, but by embracing us forever. That is his glory. If you are in Christ, whatever God is doing in your life right now is not an experiment he might abandon if he gets fed up with you. You need to know that God would have to stop being God before he'd quit on you. And why is God devoted to you? It's not because you risk looking like a failure. You already do. So do I. It's because God will never let his purpose fail. The defeat of grace to sinners would be the defeat of God.
The message of God to us all is this: "For my own sake, I love failures and fools and spiritual nitwits, for how could my name be profaned? My glory I will not give to another." God's commitment to God is his assurance to us. If that assurance does not melt your heart, it doesn't belong to you.
But if that assurance ignites within you a flame of hope, then he has set you apart to himself forever. [Remember,] the throne of God is a throne of grace (Hebrews 4:16)...God rules, and overrules, to the praise of the glory of his grace.
(Isaiah, by Ray Ortlund, Jr., pgs. 315-316; emphasis and paragraphing mine)