How do we know that faith in His name is effective for salvation?

The effectiveness of faith in Jesus' name for salvation is based on the unchanging nature of God and His promises. In Acts 3:13, Peter highlights that it is the God of Abraham, Isaac, and Jacob who glorified Jesus, affirming that God's plan of salvation has been consistent from the covenant of old. Salvation is thus not dependent on human ability but on believing that Christ, as the Son of God, fulfills all righteousness and absorbs God's wrath on behalf of His people. Believing that He does all the saving assures you of your salvation.