Hey Jai, from a biblical persprctive, this is what I have found.
You asked, "Are there any actions that are ever unforgivable? No, all actions to God are forgivable for his sake. Also note that any action will have consequences, either for the good or bad.
As Vee stated, "If a person murdered someone, and he prayed to God to ask him for forgiveness, and he means it from the heart God will forgive him. But he will still be charged by the police, locked up, tired in the Court of Law for Murder, and if he is sentenced to death he will die. But he will die receiving God’s forgiveness. "
Vee is spot on the mark with this statement. That is why Jesus' promise to save us from our sins is ever so valid. That is the reason He came, to redeem mankind back to Himself.
There is however, one sin which is unpardonable. I would like to expound on mebb's opening statement. It is the blasphemy of the Holy Ghost.
Definition: Blasphemy: n. An indignity offered to God by words or writing; reproachful, contemptuous or irreverent words uttered impiously against God.
Blasphemy is an injury offered to God, by denying that which is due and belonging to him, or attributing to him that which is not agreeable to his nature.
In Matthew 12:31 it says, "Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men."
The literal context is ascribing Jesus' exorcism to beelzebub (a devil) and not to the Holy Ghost. That was the blasphemy against the Holy Ghost.
To draw a spiritual application from the same verse in Matthew 12:31 is the denying or the rejecting of the Holy Ghost's call to you unto Jesus Christ.
Many people react in contempt to this call.
Notice in the blasphemy definition, the words contemptuous and impiously. They are defined as:
Definition: Contempt: n. 1. The act of despising; the act of viewing or considering and treating as mean, vile and worthless; disdain;
Definition: Impious: a. 2. Irreverent towards God; proceeding from or manifesting a contempt for the Supreme Being;
When you, as a person come in contact with the words or information that the Holy Ghost is giving to you personally (through another person, books, articles, bible, radio, television, etc.), and you reject it for whatever reason, you have made your decision regarding 'the calling of the Holy Ghost'. You will live with that decision for the rest of eternity. This is the blasphemy of the Holy Ghost.
Matthew 12:32 And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come.
He is the one calling you.
God will never violate man's free will. For that is how He created us. He has done all He could to provide the way to him and by rejecting his call you live with your decision. He will not come back on a decision you made for yourself.
Consider the following verse,
Hebrews 3:7-12; 7 Wherefore (as the Holy Ghost saith, To day if ye will hear his voice, 8 Harden not your hearts, as in the provocation, in the day of temptation in the wilderness: 9 When your fathers tempted me, proved me, and saw my works forty years. 10 Wherefore I was grieved with that generation, and said, They do alway err in their heart; and they have not known my ways. 11 So I sware in my wrath, They shall not enter into my rest.) 12 Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.
Jai you mentioned, "it led me to wonder if there is truly nothing that God will not forgive...you see, sometimes i feel so bad, i find it hard to believe in hell at all..."
God cannot forgive what you decided for yourself. These are predetermined parameters by God to man.
By the way, hell was not meant or intended for man.
25:41 Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels:
It's a choice you make.