Late but I wanted to chime in on the topic of salvation in Christianity.
How does one become saved?
Romans !0:8-13 NKJV
8 But what does it say? “The word is near you, in your mouth and in your heart” (that is, the word of faith which we preach): 9 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. 10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation. 11 For the Scripture says, “Whoever believes on Him will not be put to shame.” 12 For there is no distinction between Jew and Greek, for the same Lord over all is rich to all who call upon Him. 13 For “whoever calls on the name of the Lord shall be saved.”
There is no holy Abracadabra magic spell to chant nor a secret passcode that gets you into heaven. Someone who's mute isn't damned for all eternity because they can't audibly confess. It's a matter of faith and belief. The confession part, I believe at least, while important is more to strengthen your belief by verbally taking a stand, to word it very poorly. Why it's not explicitly spelled out in The Bible is an easy answer. If it were then it would turn into a legal practice that either people would nonchalantly utter as they die like in the Xavier clip, or we would twist and contort and find ways around or find ways to persecute people who didn't do it the exact right way. Faith in God and in Christ's sacrifice would be perfunctory.
To give an extreme and very shallow example: If Johnathan Yaniv/Keffals/MovieBob/Maddox/Clawshrimppy/Your favorite cow here were on their death bed and truly believed that Christ was God made flesh and died for their sins and accepted that then they would be saved. Why would they be able to do that? Because all of us have been given the same chance and God does not play favorites.
Romans 2:11 NKJV
11 For there is no partiality with God.
What God does for one he will do for another. In the story of the crucifixion of Christ there are two thieves on either side of Jesus. One mocks Jesus. The other acknowledges that he deserves this fate but Jesus does not. The second thief asks to please remember him to which Jesus accepts him and says "today you will be with me in paradise"
Luke 23:39-43
39 Then one of the criminals who were hanged blasphemed Him, saying, [j]“If You are the Christ, save Yourself and us.”
40 But the other, answering, rebuked him, saying, “Do you not even fear God, seeing you are under the same condemnation? 41 And we indeed justly, for we receive the due reward of our deeds; but this Man has done nothing wrong.” 42 Then he said [k]to Jesus, “Lord, remember me when You come into Your kingdom.”
43 And Jesus said to him, “Assuredly, I say to you, today you will be with Me in Paradise.”
Now would those people in the extreme example actually do that? As they are now, I highly doubt it. Salvation is a change of heart and I don't believe the examples I gave would let themselves go through that change. In their sudden last moments, is a person who has cursed God, denied Him, and made themselves the God of their own life really gonna go "Oh no! I better turn to the sky daddy that I never believed in so I can get into a Heaven that I never believed existed"? No. Even someone who was on the fence for years about God is not going to be in the state of mind to think about how to get saved while their bleeding out, assuming they are afforded the luxury of having the time to think. That's another good reason to not wait till the end because you might not even recognize the end coming.
The other thing that was brought up was works. You cannot buy your way into God's grace. You can not go Super Saint 3 and feed the entire world, miraculously heal cancer patients, clothe the poor, house the homeless, and have God go "Stellar work there sport. You're in." We CANNOT make it under our own power.
Isaiah 64:6 NKJV
But we are all like an unclean thing,
And all our righteousnesses are like [a]filthy rags;
We all fade as a leaf,
And our iniquities, like the wind,
Have taken us away.
Ephesians 2:8-9 NKJV
8 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, 9 not of works, lest anyone should boast.
There is bit of scripture that says "faith without works is dead."
James 2:26 NKJV
26 For as the body without the spirit is dead, so faith without works is dead also.
What that means is that there should be some evidence of your faith, a put your money where your mouth is kinda thing. This is also a good way to tell charlatans from the real deal.
Matthew 7:15-20 NKJV
15 “Beware of false prophets, who come to you in sheep’s clothing, but inwardly they are ravenous wolves. 16 You will know them by their fruits. Do men gather grapes from thornbushes or figs from thistles? 17 Even so, every good tree bears good fruit, but a bad tree bears bad fruit. 18 A good tree cannot bear bad fruit, nor can a bad tree bear good fruit. 19 Every tree that does not bear good fruit is cut down and thrown into the fire. 20 Therefore by their fruits you will know them.
Jesus fully acknowledges that people will try to buy their way into Heaven and warns them of what their fate is going to be.
Matthew 7:22-23 NKJV
22 Many will say to Me in that day, ‘Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?’ 23 And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness!’
I really hope that I got my ideas and points across. I hope it helps.