From a Lutheran perspective there needs to be a clear distinction between the Deus Revelatus and the Deus Absconditus; the Revealed God and the Hidden God.
Some aspect of that is recognizing the distinction between the Ordered Means and the Absolute Power of God. To highlight what that means, think of it this way: Fire is hot, fire burns, that is the ordered means for fire, it's what fire does. However, we read in the book of Daniel where the three companions of Daniel were put into the fiery furnace and were left completely untouched by the flames. The absolute power of God is such that here fire caused no harm, even though fire by its ordinary function does burn.
So when speaking of God as Revealed we cannot look to the Absolute Power of God, of God in His Hiddenness, in the inscrutability of His will etc, as to ascertain our faith. Instead we look upon the ordered, the revealed, the clear presentation of God in Jesus Christ. Hence our faith is not upon the mere and naked power of God, but rather our faith is in Jesus Christ who suffered under Pontius Pilate, was crucified, buried, dead, and on the third day rose from the dead.
It's why the Church has confessed throughout history, "You must be born again", and so by the order of God goes unto the nations, preaching the Gospel, baptizing them in the name of the Father, Son, and the Holy Spirit. And also that, "There is no other name by which men might be saved" except that of Christ. Or as St. Cyprian once said, "Outside of the Church there is no salvation." This has always spoken of the Church's confession of faith in Christ, of our bold faith in the Deus Revelatus: God as God has made Himself known fully, truly, and completely.
This does not deny the absolute power of God: yes absolutely God is sovereign, yes absolutely all things are within God's providence, and so on and so forth--which is why we do not consign unbaptized infants to condemnation, it's why we confess our ignorance concerning those who have never heard the Gospel, and so on and so forth. In good faith we must say that concerning things about which we are completely and as regards the absolute power of God we should remain silent, and permit the fact that God is God and we are not. If, according to God's universal will and providence all shall, in the end, be saved, then glory be to God (indeed, I very much pray and hope for this very thing). But this is a matter of the absolute power and the hiddenness of God, about which I can say nothing.
But as for faith we say that here in Christ and Christ alone is God found, because this is the Revelation of God, because here the Word of God has been made flesh.
There is always to troubling errors we can fall into: 1) That we fail to grasp the incomprehensible vastness of God and think that we can divine His inscrutable will, and so speak dogmatically on things that we can never actually speak dogmatically about; and 2) That we ignore the specificity of Jesus Christ, God the Word made flesh, apart from Whom no one can know God.
That as it pertains to the Ordered Means we have what has been revealed; and as it pertains to the Absolute Power of God only our ignorance. And so the confession of the Church must always be Jesus Christ, both in the specificity of God's Grace-in-Means (e.g. Word and Sacrament), and always hopeful and willing to be surprised by hope.
For this reason the Church can speak definitively concerning salvation in that, "Everyone who believes in him will not be put to shame."; but the Church cannot speak definitively concerning who is "in" and who is "out"; after all, God is "the Savior of all men, especially of those who believe." We know where the Church is, but not where the Church is not; we know where God's grace is, but not where God's grace is not; we know where God is, but not where God is not; we know where salvation is, but not where salvation is not.
-CryptoLutheran
