No, it is not the essense of the Gospel (of salvation). Sola fide is empty, because it is an insufficient subset of what is required for salvation. The entire set of requirements for salvation consists of holding hte concepts and values of God. If one does that and has access to the true Person of God, then they will believe in Him. That belief comes from an examination of the evidence and reference to ones own core values.
Simply believing what someone says about God is not sufficient for salvation. Works are required as I pointed out per Matt 25 and works depend on one's core values, not who one has faith in.
"So then who are these sheep who do kinds deeds to we who are the brothers and sisters of Jesus?
Pagans do kind deeds for their friends. God expects them to be done for the least of men. There are those that do that w/o ever knowing who God is and they most assuredly are saved. Some of them reject what the Churches say, because they present errors. ie. sola fide, sola sciptura and the doctrines born of them and of the democratic actions of councils. Faith is belief in what someone says and that requires trust. One who presents errors and does not use logic to correct them does not deserve trust.
God's fundamental statement on salvation is the following given in Matt 12:32, "Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come. God judges according to the values one holds and expresses in action. He said in Matt 12:7, If you had known what these words mean, ‘I desire mercy, not sacrifice,’ you would not have condemned the innocent. These two statements from God contradict sola fide absolutely and indicate no one need believe in Jesus to be saved.
Really? And why do you trust Matthew to be the definitive statement on salvation? No use for Paul? Or Peter? Or John? What if, hypothetically, I were to take the position that Matthew got it all wrong, and only Paul was right on this particular subject? Am I not a sovereign individual, empowered to pick and choose only those Scriptures that support my position? Selecta Scriptura, anyone?
“Sola fide” does not mean an inert faith is salvific, but that it is precisely the faith that is behind works that is counted for righteousness, (Rm. 5:5,10,11), “God “purifying their heart by faith,” (Acts 15:9) which manifest confirming confession in turn justifies the person as having true faith. (Rm. 10:9,10)
Thus God can require a work that requires such humble contrite faith. And as faith is shown by works, one is judged by his works as to whether he is saved, and recompensed. (Mt. 25:31-40; 1Cor. 3:8-15; 4:5) “Cast not away therefore your confidence, which hath great recompence of reward. “ (Hebrews 10:35)
And that the kind of faith that saves is one that effects obedience is what Reformers preached: http://peacebyjesus.witnesstoday.org/Reformation_faith_works.html