True knowledge of who God is and who you are, and then yeilding your life to the Lordship of Christ. It means you understand that you are a sinner, that God is holy and justly judges your sin, that Jesus is God, yet He humbled himself and became a man so that He could pay your sin debt for you. That He offers salvation to you by grace alone, through faith alone. And that faith (which encompasses repentance) is evidenced by a changed heart and a lifetime process of sanctification.
It's a lot more than a get out of hell free card.
Example of true faith: Let's say you receive tomorrow's paper today and learn that your home will be destroyed by fire tomorrow afternoon at 2:00pm. Faith means you change everything you do because of that knowledge. It's proof that you really believe it will happen. Saving faith is like that. There will be evidence that you believe in your heart that Jesus is Lord and confess that God raised Him from the dead.
Mark 1:23 And there was in their synagogue a man with an unclean spirit; and he cried out, 24 Saying, Let us alone; what have we to do with you, you Jesus of Nazareth? are you come to destroy us? I know you who you are, the Holy One of God. 5:6 When he saw Jesus from a distance, he ran and bowed down before him. 5:7 Then he cried out with a loud voice, “Leave me alone, Jesus, Son of the Most High God! I implore you by God – do not torment me!” 5:8 (For Jesus had said to him, “Come out of that man, you unclean spirit!”) 5:9 Jesus asked him, “What is your name?” And he said, “My name is Legion, for we are many.” 5:10 He begged Jesus repeatedly not to send them out of the region. 5:11 There on the hillside, a great herd of pigs was feeding. 5:12 And the demonic spirits begged him, “Send us into the pigs. Let us enter them.” 5:13 Jesus gave them permission. So the unclean spirits came out and went into the pigs. Then the herd rushed down the steep slope into the lake, and about two thousand were drowned in the lake.
Your are talking of "faith alone" needed to receive grace alone, like the Conversion of Saul in Acts 9?
Or could it be that man has little to do with his own salvation?
John 6:37 All that the Father gives me will come to me, and whoever comes to me I will never drive away. 40 For my Father's will is that everyone who looks to the Son and believes in him shall have eternal life, and I will raise him up at the last day." 44 "No one can come to me unless the Father who sent me draws him, and I will raise him up at the last day. 45 It is written in the Prophets: 'They will all be taught by God.' Everyone who listens to the Father and learns from him comes to me. 65 He went on to say, "This is why I told you that no one can come to me unless the Father has enabled him." 66 From this time many of his disciples turned back and no longer followed him.
It kind of reads like the Holy Ghost may have a hand in our salvation "true saving knowledge."