“Believers are branches in the vine who cannot do anything apart from Christ, yet at the same time they are admonished to remain in him, in his word, in his love (John 15). They are a chosen people, and still have to be zealous to confirm their call and election….They have put on the new self and must continually clothe themselves with the new self (Eph 4:24; Col 3:10)”—Herman Bavinck

“The problem with the person who does not strive toward all the fruit of faith is that he is blind in two directions. When he looks to the future, it's all a haze, and the promises of God are swallowed up in a blur of worldly longings. I think that is what it means by shortsighted. And when he looks to the past, the forgiveness that made him so excited at first is well-nigh forgotten, and all he sees is an empty prayer and a meaningless ritual of baptism. In other words, just as in verse 3 the power for godliness flows through knowledge of God, so in verse 9 blindness to the past and future work of God blocks that power and leaves us limp in the water, drifting toward destruction.”

—John Piper, Desiring God