“He who did not spare his own Son but gave him up for us all, how will he not also with him graciously give us all things? Who shall bring any charge against God's elect? It is God who justifies. Who is to condemn? Christ Jesus is the one who died—more than that, who was raised—who is at the right hand of God, who indeed is interceding for us.” — Romans 8:32-34
Election is the gracious purpose of God, according to which He regenerates, justifies, sanctifies, and glorifies sinners. It is consistent with the free agency of man, and comprehends all the means in connection with the end. It is the glorious display of God's sovereign goodness, and is infinitely wise, holy, and unchangeable. It excludes boasting and promotes humility. All true believers endure to the end.
Those whom God has accepted in Christ, and sanctified by His Spirit, will never fall away from the state of grace, but shall persevere to the end. Believers may fall into sin through neglect and temptation, whereby they grieve the Spirit, impair their graces and comforts, and bring reproach on the cause of Christ and temporal judgments on themselves; yet they shall be kept by the power of God through faith unto salvation. Those who profess faith but do not persevere, thereby show themselves to be unregenerate.