The devil’s temptations have one purpose—to cause the believer to lose faith in and despair of God’s forgiveness. We find such a temptation when the devil causes us to question God’s election or predestination of us in “eternity as a past event” (i.e. “eternity-past”). It goes something like this, "Did God elect or predestine me before the foundation of the world to salvation or am I just fooling myself?" This ordeal leads to despair over God’s forgiveness for us. If God did not elect me, no hope exists. One is left destitute and bereft of Christ, which is of course the devil’s goal. Martin Luther was no stranger to this diabolical anguish. He wrote much about his experience and pastoral counsel for it. His advice was always the same:
"When a man begins to discuss predestination, the temptation is like an inextinguishable fire; the more he disputes, the more he despairs. Our Lord God is opposed to this disputation and accordingly he has provided against it in baptism, the Word, the sacraments, and various signs. In these we should trust and say: “I am baptized, I believe in Jesus Christ; what does it concern me, whether or not I am predestined?’ He has given us ground to stand on,that is, Jesus Christ, and through him we may climb to heaven. He is the one way and the gate to the Father. ... In these we should trust and say: ' I am baptized, I believe in Jesus Christ; ...”
The presence of God in Word and sacrament is no small comfort. First, the sacrament is given to you and for you in particular. We should "grab hold of our noses" and realize it was water put on you and the body and blood of Jesus given and shed for you for the forgiveness of your sin put in your mouth. God comes to you in these with the Gospel, forgiveness and eternal life, so that you unquestionably know!
However, the consolation doesn’t end there. God’s gifts keep giving. You cannot exhaust baptism and the Lord’s Supper.
Satan’s subtle trick about election is rooted in a false notion about what eternity is. The usual definition for eternity is “infinite time”. "So," goes the devil’s logic, "did God elect to save me in eternity-past?" However, eternity is not “infinite time” in which God dwells. If that were true, eternity itself would be god—that is, one attribute we know to be an attribute of God would seem to come before all others to the point we could imagine it existing without Him.
The big division between all things is between Creator and creature. The Nicene Creed states God is the "Creator of all things visible and invisible". God alone was in the beginning before all things, and all things other than God are created creatures through God (Gen 1 and John 1:1-2). This includes things we rarely consider “creatures” such as angels, time, space, material, forces, living beings, etc. The Apostle John writes, "Through him all things were made; without him nothing was made that has been made" (John 1:3). Before all things were created only God existed and time is a creature whose Lord and Creator is God.
The prophets and the apostles testify to this throughout Scripture:
“Trust in the Lord forever, for the Lord, the Lord himself, is the Rock eternal.” (Isa 26:4)
“You search the Scriptures because you think that in them you have eternallife; it is these that testify about Me” (John 5:39)
The baptized are told we will inherit eternal life (Matt 19:29) and eternal life is none other than Christ Himself, “I am the way, the truth and the [eternal] life, no one comes to the Father except through Me.” (John 17:3).
Furthermore, God is a Trinity not a “quadrinity” (Apostles, Nicene and Athansian Creeds). Eternity is of the essence of God and not a fourth divine person of the Godhead.
This is no philosophical musing or religious speculation. This is a confession of the Christian faith:
“And the catholic (i.e. universal Christian) faith is this: That we worship one God in Trinity, and Trinity in Unity; Neither confounding the persons nor dividing the substance. For there is one person of the Father, another of the Son, and another of the Holy Spirit. But the Godhead of the Father, of the Son, and of the Holy Spirit is all one, the glory equal, the majesty coeternal. Such as the Father is, such is the Son, and such is the Holy Spirit. The Father uncreated, the Son uncreated, and the Holy Spirit uncreated. The Father incomprehensible, the Son incomprehensible, and the Holy Spirit incomprehensible. The Father eternal, the Son eternal, and the Holy Spirit eternal. And yet they are not three eternals but one eternal...”. [Athanasian Creed]
Since there are not “three eternals” in the Trinity but One Eternal, there are no other eternities! This eternal or eternity is God Himself!—that is, where we find eternity, we find God in His fullness, with all His other attributes.
So, how do we know that we are elect from eternity and saved, possessing eternal life? The Creator is united with the creature in the Lord Jesus Christ. This Jesus, who IS God, comes into our particular time and space in our part of history in the Word, our baptism, and the Lord’s Supper and elects us.
Since God elects us in the time and space of our baptisms, the devil’s debate is lost. Why? Because the One Eternal God came to me and you in person and did the deed of electing us when we were baptized!