Your parents believe a lot of common myths that people who are unsaved (or super immature in Christ) believe.
God's people perish for lack of knowledge. I have gone through your parents' beliefs in this post and provided Bible verses that directly address (i.e. correct) those false beliefs. You can use these verses to give them the truth, and pray that they receive it in their minds and hearts.
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Almost my whole family thinks everyone, as long as they are pretty good goes to Heaven.
Romans 3:10-12 - "
There is no one righteous, not even one; there is no one who understands; there is no one who seeks God. All have turned away, they have together become worthless;
there is no one who does good, not even one."
Romans 3:23-25(excerpt) - "
for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is Jesus Christ, whom God put forward as a propitiation by his blood, to be received by faith."
(So no one is good, and no one is good
enough.)
My father in particular believes the Bible was written by men who may have gotten things wrong
2 Timothy 3:16 - "
All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness"
1 Corinthians 2:12-13 - "What we have received is not the spirit of the world, but the Spirit who is from God, so that we may understand what God has freely given us. This is what we speak,
not in words taught us by human wisdom but in words taught by the Spirit, explaining spiritual realities with Spirit-taught words."
2 Peter 1:21 - "For
prophecy never had its origin in the human will, but prophets, though human,
spoke from God as they were carried along by the Holy Spirit."
and that all religions have a part of the truth.
John 14:6 - "I am the way,
the truth, and the life.
No one comes to the Father except through Me." (Meaning other religions won't get you to Heaven, nor are they the truth. Jesus said this quote, by the way.)
Isaiah 45:5 (excerpt) - "I am the Lord, and there is no other;
apart from me there is no God." (Other gods are false; no god is like our God.)
Romans 1:20-25 - "For since the creation of the world God's invisible qualities--his eternal power and divine nature--have been clearly seen, being understood from what has been made, so that people are without excuse. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like a mortal human being and birds and animals and reptiles. Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. They exchanged the truth about God for a lie, and worshiped and served created things rather than the Creator--who is forever praised. Amen." (This is about false religions. They exchanged the truth, so they don't have it. They have a lie.)
1 John 2:22 (excerpt) - "
Who is the liar? It is whoever denies that Jesus is the Christ." (Other religions deny that Jesus is the Christ. They lie.)
My mother claims to believe the Gospel but also that almost everyone goes to Heaven. It's hard to go up to them and talk about Christianity because they'll agree with almost everything the Bible says, but not that many 'good' people will go to Hell for not believing in God.
Matthew 7:13-14 - "Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it.
But small is the gate and narrow is the road that leads to life, and only a few find it." ("Only a few" is not "almost everyone".
Most people are going to Hell.)
John 3:16 - "For God so loved the world He gave His only begotten Son, that
whoever believes in Him will never die, but have eternal life." (That's not just anybody; they have to
believe.
That's the Gospel.)
John 3:17-18 - "For God did not send His Son into the world to condemn the world, but to save the world through him. Whoever believes in him is not condemned, but
whoever does not believe stands condemned already because they have not believed in the name of God's one and only Son." (Therefore, people in fact
do and
will go to Hell for not believing in Jesus.)
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I think this article, "
How do I get to Heaven?: 10 Questions the Bible Answers" will be of particularly good use to you. It addresses some of your parents' objections and then some. In fact, both you and them could benefit from reading it.
I hope this helps!
