The dart of death or the sting of the wicked is sin. By taking the shield of faith we can overcome sin. Because though faith sin is forgiven:
To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me. Acts 26:18
Through the sanctification of faith, sin is forgiven, the darts will be quenched.