How do we know the teaching of God's long-suffering is true?

God's long-suffering is prominently illustrated in 2 Peter 3:9, where it states that He is 'not willing that any should perish, but that all should come to repentance.' However, this is not a universal statement about all of humanity; rather, it is directly related to the elect, those whom God has chosen. This long-suffering reflects His character and intention—the patience expressed is aimed at a specific group, encouraging them towards repentance. It is essential to understand this in light of God's sovereign grace, which affirms His commitment to His chosen ones and His active work within their lives to bring them to salvation.