Michael Horton on Assurance of Election

"Scripture itself teaches us to draw assurance from God’s unconditional election. Believers are not taught to doubt or question their election, but to “make [their] calling and election sure” (2 Peter 1:10). Jesus promised that he will gather his elect from the whole earth and deliver them from the wrath to come (Mark 13:27). He cares for his elect and answers their cries (Luke 18:7) and assures his own that they are chosen not only to be saved but to be preserved in that grace (John 13:18; 15:16). Who can charge against God’s elect, since Christ has died for their sins and even now intercedes for them at the Father’s right hand (Rom. 8:33)? Sometimes storming out of the room, my father used to react viscerally whenever, as a teenager, I was debating election with my mother. On one occasion, I followed him outside and apologized for raising the subject when he made it clear that it offended him. Turning to me with tears, he asked, “What if your dad’s not one of the elect?” It is so easy for us to turn gospel into law, faith-creating good news into anxiety-generating questions. It is true that in some circles election is not understood as a comforting and assurance-producing doctrine, but the very opposite. In some pietistic circles, a Christian can refrain from receiving communion for years — even over a lifetime — out of a lack of assurance concerning his or her election. However, this is not how we find election taught in Scripture. In response to my dad’s question, I quoted Jesus’ words in John 10:27: “My sheep hear my voice, and I know them, and they follow me.” “Have you heard his voice and followed him?” I asked. “Yes,” he replied. “Then this is Jesus’ answer to you in the next verse: ‘I give them eternal life, and they will never perish, and no one will snatch them out of my hand.’ “ Everything changed, even in his countenance. Once he understood that point, election became the opposite of what it had been before to him; it was now a marvelous comfort. He would always say thereafter that this was a life-changing moment."

Horton, Michael S. (2011-10-11). For Calvinism (Kindle Locations 1240-1257). Zondervan. Kindle Edition.