The only thing necessary to change heaven into hell -- if God were to allow it -- is selfishness. Selfishness is mankind's fundamental defect. Selfish means: self-centred, self-serving, self-important. At the root of every problem is selfishness.
“For where envying and strife is, there is confusion and every evil work.” (James 3:16) Every selfish person is potentially your enemy. Giving is the opposite of acting selfishly. Divine love is the opposite of selfishness. No other "religion" teaches to put others first, to love your enemies. Christianity is the only one that teaches you can be totally changed and become a person with a new nature.
We are products of a corrupt culture that teaches selfishness. All sin is selfish. No one ever sins for someone else -- we do it for selfish reasons. We must die to selfishness -- or self-destruct. However, we are unable to do it by ourselves. We must allow Jesus Christ to change us inwardly. You can't change the fruit without changing the root. That is why you must be born again! Only by receiving Jesus Christ, and letting Him change you, can you be a truly unselfish person.
Pride
Pride is self-importance and self-focus -- which leads to selfishness which is selfish thinking and selfish acting -- which is the opposite of Jesus' command of agape love.“A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. By this all people will know that you are my disciples, if you have love for one another.”(John 13:34)
Pride and selfishness always go together. A truly humble person cannot be selfish at the same time. Pride is the root of selfishness -- and thus the root of all evil. Pride is hidden but manifests as selfish acts. Selfishness is the cause of all evil. All evil proceeds from selfish actions. Selfishness is the only manifest problem, but pride feeds it. Dealing with the root cause of the problem is the only lasting solution. Pride produces selfishness. All selfishness is pride. Doing things yourself, on your own, is a part of selfishness. Prayer is the opposite of doing things yourself. We must desire God's: will, done in God's time, and done God's way.
Selfish Ambition
“Now the works of the flesh are evident: sexual immorality, impurity, sensuality, 20 idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.”(Galatians 5:19-21)
“Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves. Let each of you look not only to his own interests, but also to the interests of others.” (Philippians 2:3-4)
It takes faith to put others first. It takes faith to receive, but it takes even more faith to forsake -- because it does not seem to be in our self-interest. “By faith he left Egypt, not being afraid of the anger of the king, for he endured as seeing him who is invisible.” (Hebrews 11:27)Deny Yourself
And he said to all, “If anyone would come after me, let him deny himself and take up his cross daily and follow me. For whoever would save his life will lose it, but whoever loses his life for my sake will save it. For what does it profit a man if he gains the whole world and loses or forfeits himself?”(Luke 9:23-25)
The Bible instructs us to deny ourselves -- not condemn ourselves. Our choices must be based on doing God's will -- not just in pleasing ourselves. God is not against pleasure -- He invented it! But it should be your slave -- not your master.
“For you have died, and your life is hidden with Christ in God.”(Colossians 3:3)“For the love of Christ controls us, because we have concluded this: that one has died for all, therefore all have died;15 and he died for all, that those who live might no longer live for themselves but for him who for their sake died and was raised.”(2 Corinthians 5:14-15)
Put Others First
“For this is the message that you have heard from the beginning, that we should love one another. We should not be like Cain, who was of the evil one and murdered his brother. And why did he murder him? Because his own deeds were evil and his brother's righteous. Do not be surprised, brothers, that the world hates you. We know that we have passed out of death into life, because we love the brothers. Whoever does not love abides in death. Everyone who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him. By this we know love, that he laid down his life for us, and we ought to lay down our lives for the brothers. But if anyone has the world's goods and sees his brother in need, yet closes his heart against him, how does God's love abide in him? Little children, let us not love in word or talk but in deed and in truth.”(1 John 3:11-18)
“Love one another with brotherly affection. Outdo one another in showing honour.” (Romans 12:10) “For though I am free from all, I have made myself a servant to all, that I might win more of them.”(1 Corinthians 9:19)“Let no one seek his own good, but the good of his neighbour. Just as I try to please everyone in everything I do, not seeking my own advantage, but that of many, that they may be saved.” (1 Corinthians 10:24,33)
“Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves. Let each of you look not only to his own interests, but also to the interests of others. 5 Have this mind among yourselves, which is yours in Christ Jesus, who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant, being born in the likeness of men. And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross.”(Philippians 2:3-8)
We who are strong have an obligation to bear with the failings of the weak, and not to please ourselves. Let each of us please his neighbour for his good, to build him up. For Christ did not please himself, but as it is written, “The reproaches of those who reproached you fell on me.”(Romans 15:1-3)
Selfishness Is Opposite Love
“This is my commandment, that you love one another as I have loved you. 13 Greater love has no one than this, that someone lay down his life for his friends.”(John 15:12-13) “For the whole law is fulfilled in one word: “You shall love your neighbour as yourself.”(Galatians 5:14)“Love is patient and kind; love does not envy or boast; it is not arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrongdoing, but rejoices with the truth. Love bears all things, believes all things, hopes all things, endures all things.”(1 Corinthians 13:4-7)