To attempt to make this simple, Catholicism teaches that God does not just forgive a sin and it's done with. The sinner must also suffer temporal punishment, and then time in Purgatory. But Urban was also the catalyst for the Crusades. He needed soldiers. So he declared that anyone who fought in the First Crusade was absolved of all sin. If you could not go for some reason or other, you simply bought your way out with something called an "indulgence." Partial indulgences were also offered, which presumably cost less, and a complex system developed wherein they claimed they could calculate to the day how many of your sins had been cancelled by the amount you paid. Although in the beginning it was assumed one would also perform acts of penance, within a few centuries that part no longer mattered. Plus, you could even buy a dead loved one out of Purgatory!
This is one of the things that finally pushed Martin Luther to rebel. When he hanged those 95 Theses on the church door, indulgences were squarely in his view as one of the worst kinds of corruption in the Catholic Church. Finally, Pius V abolished them in 1567. It had become obvious to even the bean counters how venal the whole system was.
Of course we know that none of this is found in the Bible—not even a place called Purgatory. God says that when we meet His conditions, He will forgive us. Period. Though your sins be as scarlet, they shall be as white as snow, He promised as early as Isaiah (1:18). Aren't we glad that with God things are so simple? But today, you still see people creating indulgences, ways to make themselves and their sins not count against them.
"The church is full of hypocrites." In my experience that isn't even true. Yes, we might see a few, but certainly not 100%. Even the apostles weren't immune from that problem. And just how does that make it okay to ignore God's commands even if it were true? It will not cause God to "indulge" your little foibles.
"It's the way I was brought up. I can't help myself." Well, Abraham was brought up by idolaters (Josh 24: 2), but somehow or other he overcame that upbringing and became "the Father of the Faithful" and "the Friend of God." Both Hezekiah and Josiah were sons of wicked kings who worshipped idols and made treaties with the enemies of God, yet became two of the most righteous kings Judah ever had. So now, what was that "indulgence" you thought you deserved?
"The preacher preached a sermon that hurt my feelings." Jesus hurt a few feelings himself and never apologized for it. Then came the disciples, and said unto him, Don't you know that the Pharisees were offended, when they heard this saying? But he answered and said, Every plant which my heavenly Father planted not, shall be rooted up. Let them alone: they are blind guides. And if the blind guide the blind, both shall fall into a pit (Matt 15:12-14). Jesus said that if they let themselves be offended and did not listen to his teaching and change, that they would be "rooted up," not excused. Most preachers I know quote the Word of God. Those words are the ones that "hurt people's feelings." Jesus doesn't give "indulgences" that will absolve your sin when that happens. You always have the choice not to be offended, but to repent and change. Take heed how you hear, Jesus also said (Luke 8:18).
And it is probably not unheard of for someone to tell a congregation, "I give a whole lot more than any of you. That means you had better_______ (do things my way, stop preaching about things I (or my family) am doing, etc.), or we're leaving. I do know of one who told the elders if they didn't get rid of a certain Bible class teacher they, and their contribution, would leave. If that isn't buying indulgences, I don't know what is.
Even the Catholic Church finally realized the sleaze factor in indulgences and got rid of them. We need to follow suit. God is a loving and merciful parent, but He is never indulgent toward unrepented of sin.
Therefore the wicked will not stand in the judgment, nor sinners in the congregation of the righteous; for the LORD knows the way of the righteous, but the way of the wicked will perish (Ps 1:5-6).
Dene Ward