"For I am not ashamed of the gospel of Christ, for it is the power of God to salvation for everyone who believes, for the Jew first and also for the Greek. For in it the righteousness of God is revealed from faith to faith; as it is written, 'The just shall live by faith.'"
By faith alone, through His grace alone, for His glory alone.
Faith: Belief in Jesus Christ, God's son, fully God who humbled Himself, became man, killed by men, took the wrath and punishment of God ONE time, dead for 3 days, rose on third, ascended to heaven and there He sits at the right hand of the God the Father.
Grace: God demonstrated His grace by sending His son Jesus to be a man, die, take the punishment that the just God must give, and we are now not only forgiven but adopted as heirs - as sons of God, just as Jesus Christ.
His Glory: Why would God do all of this? Because He is perfect, holy, righteous, and it declares His glory to the world. He's the main thing.
How am I to be saved? Only through faith. Only by making Him Lord/Master of your life. Going to church, paying money to the church, confessing your sins, believing that Jesus existed, taking part in communion, or living a good life, or any other work isn't enough, one must have faith, must submit as a slave to the great Master who is perfectly good, loving, holy, righteous, just, powerful . . .