Most people are fairly conservative, and it takes a lot of effort to get them to change their ingrained habits. The Old Testament contains repeated patterns of the people of Israel renewing their covenant with God, then failing to change their habits and going astray. Jesus came to offer a new covenant which did not require frequent sacrifices to atone for frequent sins. Chapter 8 of the Letter to the Hebrews says:
High priests are appointed to offer gifts and sacrifices… What they do is a copy and shadow of the heavenly things… But now Jesus has received a superior ministry, and he is the mediator of a superior covenant, which has been established on superior promises. If there had been no problems with that first covenant, there would have been no reason to look for a second.
The problem is that most people are no more inclined to agree to the new covenant than they were to abide by the old. Given the choice between wallowing in sin and experiencing a restored relationship with the God of the Universe, most people prefer the tried and familiar path of wallowing in sin, either choosing to disregard God entirely or hoping to get into heaven on their own merits without ever having had to renounce the fleeting pleasures of sin.