Hi, Daddy’s Girl!
Yes! It was Jesus death on the Cross that took away our sins:
6 You see, at just the right time, when we were still powerless, Christ died for the ungodly. 7 Very rarely will anyone die for a righteous person, though for a good person someone might possibly dare to die. 8 But God demonstrates his own love for us in this: While we were still sinners, Christ died for us. (Romans 5:6-8)
…while, His Resurrection and Ascension into Heaven Granted us access to the Father, Who is in Heaven:
9 Since we have now been justified by his blood, how much more shall we be saved from God’s wrath through him! 10 For if, while we were God’s enemies, we were reconciled to him through the death of his Son, how much more, having been reconciled, shall we be saved through his life! 11 Not only is this so, but we also boast in God through our Lord Jesus Christ, through whom we have now received reconciliation. (Romans 5:9-11)
And…all the millions or billions of people who lived good, honest, loving lives and died before Jesus arrived…they did not get to heaven? (at least, not until Jesus arrived?).
I think you’ve missed the part about Jesus’ atonement for sin (due to text limit I will select only certain parts of the quote:
31 (…) If God is for us, who can be against us? 32 He who did not spare his own Son, but gave him up for us all—how will he not also, along with him, graciously give us all things? 33 (…) It is God who justifies… 35 Who shall separate us from the love of Christ?.. 38 For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, 39 neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord. (Romans 8:31-39)
18 For Christ also suffered once for sins, the righteous for the unrighteous, to bring you to God. He was put to death in the body but made alive in the Spirit. 19 After being made alive,[d] he went and made proclamation to the imprisoned spirits— 20 to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built. (1 St. Peter 3:18-20)
So you see, God’s been there and done that! Jesus died for sin–all sin: past, present, future (no that does not mean that we can sin till we die like rebels without a cause). God is Omnipotent. He exists in NOW (Yahweh: I AM). Salvation is God’s Free Gift for all–since, as you’ve pointed out, millions died prior to the Incarnation of the Word, God made a concession for them (as St. Peter explained)–so we need not worry about securing their Salvation for them, Jesus already saw to that!
Why would God wait so long to do this? Why keep people in hell or purgatory for so long and wait so long before sending Jesus here to suffer, die, come back to life…so that people can then possibly get to heaven?
Since God is Omnipotent and Omniscient, He knows why… you and I, well we can hardly tell the time of day sometimes, right?
So…all this…just because Adam and Eve ate the fruit?
…yeah, not! The key you are missing is: disobedience; Adam and Eve took the word of the creature instead of the Creator and obeyed the creature rather than the Creator, thusly, rejecting God’s Authority over them.
People here often say that a person can be saved at the last minute no matter what life they led before that, if they embrace/call out to God.
Is that true or not?
In the realm of possibilities all things are possible. Yet, though the Holy Spirit is able to intercede in our behalf, I would not wager much on final moments’ repentance and enlightenment–that is, a person who’s whole life have been spent rejecting God’s Authority (in my opinion) has a snowball change in Hell in making a true surrender and repentance. Remember, it is not just claiming to Believe but actually Believing God and in God; it is not just asking for Salvation but accepting everything that goes with it (God’s Authority, Power, Mercy, and Grace).