God chose you as the firstfruits to be saved, through sanctification by the Spirit. (2 Thessalonians 2:13)
The Bible speaks of our election — God’s choosing us — in Christ before the foundation of the earth (Ephesians 1:4) before we had done anything good or evil (Romans 9:11). Therefore, our election is unconditional in the strictest sense. Neither our faith nor our obedience is the basis of it. It is free and utterly undeserved.
On the other hand, dozens of passages in the Bible speak of our final salvation (as opposed to our election in eternity past) as conditional upon a changed heart and life. So, the question arises, How can I have the assurance that I will persevere in the faith and holiness necessary for inheriting eternal life?
The answer is that assurance is rooted in our election. Second Peter 1:10 says, “Be all the more diligent to confirm your calling and election, for if you practice these qualities you will never fall.” Divine election is the foundation of God’s commitment to save me, and therefore that he will undertake to work in me by sanctifying grace what his electing grace has begun.
This is the meaning of the new covenant. Everyone who believes in Jesus is a secure beneficiary of the new covenant, because Jesus said in Luke 22:20, “This cup that is poured out for you is the new covenant in my blood.” That is, by my blood I secure the new covenant for all who are mine.
In the new covenant God does not merely command obedience; he gives it. “The Lord your God will circumcise your heart and the heart of your offspring, so that you will love the Lord your God with all your heart and with all your soul, that you may live” (Deuteronomy 30:6). “I will put my Spirit within you, and cause you to walk in my statutes” (Ezekiel 36:27; cf. 11:20). Those are new covenant promises.
Election is God’s eternal commitment to do this for his people. So, election guarantees that those whom God justifies by faith he will most assuredly glorify (Romans 8:30). This means that he will unfailingly work in us all the conditions laid down for glorification.
Election is the final ground of assurance because, since it is God’s commitment to save, it is also God’s commitment to enable all that is necessary for salvation.