The Bible says that darkness shall cover the earth, an gross darkness, the people. It is Satan is the major reason people are covered by darkness. He has blinded the minds of people who believe not, not allowing the light of the glorious gospel of Christ to shine for them.
Question: Will a man be saved if he asked for forgiveness from God when he is at the point of death?
Asking for God's mercy at the point of death is wickedness. One shouldn't wait till the dying moment to ask for mercy. We should obey God's laws while still active.
God would laugh at such people when their calamities befall them.
Proverbs 1:24-29
Because I have called, and ye refused; I have stretched out my hand, and no man regarded;
But ye have set at nought all my counsel, and would none of my reproof:
I also will laugh at your calamity; I will mock when your fear cometh;
When your fear cometh as desolation, and your destruction cometh as a whirlwind; when distress and anguish cometh upon you.
Then shall they call upon me, but I will not answer; they shall seek me early, but they shall not find me:
For that they hated knowledge, and did not choose the fear of the Lord
we should serve God while still active.
Question: Aside from the Bible, is there any other source of salvation for man?
The Bible is a book written by the inspiration of God. It came from God. The Bible it's authenticity by itself.
It is only God that can declare the end from the beginning.
Isaiah 46:10
Declaring the end from the beginning, and from ancient times the things that are not yet done, saying, My counsel shall stand, and I will do all my pleasure.
So there's no other book comparable to the Bible, and there is no other source of salvation for man, apart from God.
Question: Is it allowed in the Bible to undergo surgery?
Surgery is allowed because it's aims to save lives.
God was the first to performed surgery when he took the rib of Adam to form Eve.
Thanks be to God.