2 Peter 1:10

give diligence to make your calling and election sure We hardly need to prove that the "calling and election" of which St Peter speaks were thought of by him as Divine acts according to the Divine foreknowledge (1 Peter 1:2; 1 Peter 2:21). He was not hindered, however, by any speculative difficulties from admitting that it was in man's power to frustrate both (comp. 2 Corinthians 6:1; Galatians 2:21), and that effort was required to give them permanent validity. They were, from his point of view, as the conditions of a covenant offered by God's mercy, but it remained with man to ratify or rescind the compact.

ye shall never fall More literally, and more significantly, ye shall never stumble, "stumbling" being, as in Romans 11:11, a step short of falling. The use of the word may be noted as presenting a coincidence with the language of St James (James 2:10; James 3:2).