There's a lot of truth to Solomon's wise phrase, "there's nothing new under the sun." The temptation to make religion a game is just as present now as it was thousands of years ago. In fact, the Israelites were great at playing it. Here's how it worked: they would sin all they wanted, and then they would go and confess their sins. When they were finished confessing, they would go back to sinning until their next confession. Sound familiar? I know I've found myself in the same vicious cycle on more than one occasion. I think that's why Isaiah's words in 1:13b ring so true with me: "I cannot endure iniquity and solemn assembly." God was tired of the game, and He was tired of the Israelites believing that they could play Him. He didn't want sin and repentance any longer; He wanted changed hearts.
Are you in a cycle of sinning with the trust that God will forgive you later if you just ask and quote a few verses? If so, Isaiah's words are just as relevant to you as they were to the Israelites. God doesn't delight in the sin game – He desires changed hearts. The changed heart doesn't rely on God's forgiveness as a motivation to sin. Instead, it seeks ot avoid sin because it knows the pain that it causes to the One it loves. That's the difference between religion as a game and a relationship with a heavenly Father.