Christianity ?

Become Catholic. Avail yourself of the Sacrament of Reconciliation. Then, never look back.

You can't undo the past, but you can know that your sins are forgiven. The moment you believe in Jesus Christ as your Savior, ALL of your sins (past, present and future) are completely forgiven (Acts 10:43).

The truth is that death leads to heaven or hell, and the only way to heaven is through faith in Jesus Christ.

The Bible is very clear that no one can earn their way to heaven since good works do not pay for sins. See Gal. 2:16, Rom. 3:23-28, 4:4-5, Eph. 2:8-9, Tit. 3:5. The only way to heaven is by believing in Jesus for His free gift of eternal life. Jesus shed His blood on the cross as the full payment for our sins. He did all the work; all He requires of us is that we believe in Him. Once you believe in Jesus Christ to save you, you are secure forever!

Because we have all sinned against a perfectly holy and righteous God, we all deserve eternal separation from God in hell (Rom. 6:23). However, God loves us so much that He sent His only Son Jesus to die on the cross as our Substitute so we don't have to go to hell. Christ died for our sins, was buried, and rose from the grave three days later (1 Cor. 15:3-4). He gives eternal life freely to anyone who simply believes in Him for it. No one can be saved by doing good works. Salvation is by grace alone through faith alone in Christ alone (Eph. 2:8-9).

"Verily, verily, I say unto you, He that believeth on me hath everlasting life" (John 6:47).

He not only can forgive any sin, He very much wants to, so as many of His beloved human children as possible can join Him in Heaven. Which is why He gave us the holy sacrament of Reconciliation, also known as Confession, through which every sin we have ever committed can be totally washed away, leaving us spiritually pure.

No, it isn't.  There is no forgiveness for murder (only eventual redemption from hell), nor for the sin against the Holy Ghost (never).  Aside from those, Christ is powerful enough to help you repent and become pure.

i think its true, talk to god about it

Yes, he not only forgives any sin, he already has forgiven all sin.  All you need to learn is to step into it and accept it.  It’s a hard thing for us humans to do.

The only unforgivable sin is rejecting Jesus Christ as your personal Lord and Savior.  Look up these Bible verses:  John 3:16, 1:12, John 14:6, 3:3; Romans 3:23, 6:23, 5:8, 10:13, 10:9&10; Ephesians 2:8,9.  Humbly confess all known sin to God and ask His forgiveness.  Ask Jesus into your life as Lord and Savior.  Follow Him as best you can.  Read at least a chapter or  two of the New Testament daily.  I suggest starting with the Gospel of John.  Pray daily.  Use the Lord's Prayer (Our Father, ,etc.) as an outline for prayer.  It's in Matthew, Chapter 6.  After you finish the New Testament, read Psalms, Proverbs and Genesis before tackling the rest of the Old Testament. 

They only unforgivable sin is blasphemy of the Holy Spirit. Repent of your sins and you'll be forgiven.  Then you can forget about whatever you did in the past.

Yes, even if you murdered God's son.

Act 2:36  Let all the house of Israel therefore know for certain that God has made him both Lord and Christ, this Jesus whom you crucified.” 

Act 2:37  Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, “Brothers, what shall we do?” 

Act 2:38  And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit. 

2 Peter 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.

1 John 1:9 If we confess our sins, he is faithful and just to forgive us [our] sins, and to cleanse us from all unrighteousness.

God will forgive any sin but keep in mind, asking forgiveness of sin is not what saves you. It's part of it, but salvation is you calling upon the Lord as a sinner. Romans 10:9-13. 

1 Timothy 1:15 This is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners; of whom I am chief.