What does it mean that the long-suffering of the Lord is salvation?
The long-suffering of the Lord is salvation because God's patience serves His main concern: bringing salvation to a fallen human race. From Genesis 3 to the end of Scripture, Christ is presented so people can find salvation, and His forbearance gives time for that saving purpose.
Les explains that from Genesis 3 to the end of the Book, Scripture is trying to bring about the salvation of a fallen human race. In that regard, Christ can be found in one form or another on almost every page, because this is God's main concern: that the human race can find salvation. The long-suffering and patience of the Lord is salvation, even as Paul wrote according to the wisdom given to him. Peter, steeped in Judaism, legalism, Temple worship, Christ's earthly ministry, and the Old Testament covenant promises, had to admit that God was no longer dealing with Israel on the covenant promises, but was out to bring salvation to the whole human race. Some things are hard to be understood, and the unlearned and unstable twist them to destruction.