Patching up new garments to old ones. Putting new wine in old wineskins. Two analogies Jesus used to bring home one simple truth: regeneration is an all or nothing deal. Either you embrace it all or you don’t have it at all.
There is no middle ground. No custom-made Christianity. When it comes to obeying God, you don’t have the option to choose the features you like and relegate to the background the stuff you’re not comfortable with.
Patchwork Christianity is when you try to do a mashup of old life and new life. Grace with a tinge of legalism. Faith and a fair amount of good works. Trusting while secretly worrying. Not only does it NOT work, it also ruins the beauty that God intended in the first place.
In reality, patchwork Christianity is wrong in at least two counts. It’s tiresome because it forces you to do the work of God with your own strength. This leads to legalism and self-righteousness. It’s also a form of pride because it indirectly tells God that you can do it without his help. Either way, it’s your loss.