1. Is OSAS (Once Saved, Always Saved) Biblical?
Yes. Consider the following passages:
At that time the Feast of Dedication took place at Jerusalem. It was winter, and Jesus was walking in the temple, in the colonnade of Solomon. So the Jews gathered around him and said to him, "How long will you keep us in suspense? If you are
itheChrist, tell us plainly." Jesus answered them, "I told you, and you do not believe. The works that I do in my Father's name bear witness about me, but you do not believe because you are not among my sheep.
My sheep hear my voice, and I know them, and they follow me. I give them eternal life, and they will never perish, and no one will snatch them out of my hand. My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father's hand. I and the Father are one." (John 10:22-30;
ESV)
As can be seen, those who are the sheep are placed in the hands of Christ by the Father. No one can snatch the sheep out of the hands of Christ or the Father. Someone cannot come into their hands and leave.
Jesus said to them, "I am the bread of life; whoever comes to me shall not hunger, and whoever believes in me shall never thirst. But I said to you that you have seen me and yet do not believe. All that the Father gives me will come to me, and whoever comes to me I will never cast out. For I have come down from heaven, not to do my own will but the will of him who sent me. And this is the will of him who sent me, that I should lose nothing of all that he has given me, but raise it up on the last day. For this is the will of my Father, that everyone who looks on the Son and believes in him should have eternal life, and I will raise him up on the last day." (John 6:35-40; ESV)
Again, those who come to Christ will not be cast out. Those who come to Christ will not be lost and will be raised up on the last day. This corresponds with Philippians 1:6, which states that "he who began a good work in you will bring it to completion at the day of Jesus Christ."
2. If a Christian refuses to spread the Gospel, are they going to hell?
A Christian will not refuse to share the Gospel. Good works are prepared for us by God when he brings us to faith in Him:
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them. (Ephesians 2:8-10; ESV)
3. Is it
truly by
faith, and not
works that we are saved?
Yes. Read the above citation of Ephesians 2:8. Galatians 3:24 states that we are justified by faith.
I pose these questions due to a video I saw online. Supposedly a Korean Artist had a tour of hell with Jesus, and during the tour, she said that Christians who don't share the Gospel, or don't find sharing the Gospel as important will go to hell. Is this true?
Someone who has no desire to share the Gospel is probably not a Christian, as they clearly have no conviction. A genuine Christian will show good fruits and try their best to walk in the statutes of God.