Here's a point I didn't have time for in the sermon...
In Egypt, Abram is far from the altar of the LORD and so he's far from calling on the Name of the LORD. It's the altar of the LORD that makes sense of the Name of the LORD.
Think of where Abram's altar is. It's on a mountain ridge between Bethel and Ai. "Bethel" means “house of God” and "Ai" means “ruin”. To the west lies the presence of the Lord. To the east lies a ruin. And this hilltop place of sacrifice stands between them. Where God’s house meets our ruin – there is bloody sacrifice.
At the altar God meets our ruin and provides the blood that saves. Here sinners can call on the true Name of God. Through the blood of the sacrifice we find that the LORD truly is "the compassionate and gracious God..." (Exodus 34:6ff). But who can call on the gospel character of Christ when they are far from His altar??
Abram shows what happens when we stray from the cross. Having sinned, he gives us a picture of a spiritual sulk. In Genesis 13:3, he moves through the “Negev” - the "wilderness" - going from place to place. Moping in the dryness, moping around the fringes of the promised land.
Isn't this what we all do when we fail? I do. I put myself in a self-imposed “time-out” with God. I try not to bother Him for a while and hope He forgets what I’ve done. But no, time doesn’t atone for our sins. Tears don’t atone for our sins. The LORD Himself provides our atonement.
So then, let's flee to the cross, let's know the blood of the LORD Jesus. Let's not mope around on the fringes of His promise, let's not try to clean ourselves up. Let's come to Christ for the bath. Then we will call on His gospel character - the Name that makes sense at the altar.