One of the dangers of [obedience based Christianity] is that it can lead people to think God owes them a reward for their obedience. Their perspective in life is:

• ‘If I do certain things, I expect God to come through for me’.   And when He doesn’t, they think: What’s wrong? Why isn’t He doing something to help me, and what can I do?
• In the opposite direction, some people live in fear that because of their sin, God will punish them…This is a trap.

If we think we earn God’s favor by our obedience or disfavor by our disobedience, we will expect God to come through for us or, at the other extreme, will always be living in fear that ‘the other shoe will eventually drop’.

~ Jerry Bridges, from The Transforming Power of the Gospel