Let's look at an example of healthy and unhealthy boundary setting with an adult child. Let's say you are the parent of a large family. Your oldest daughter is self-supporting, but she's living with a boyfriend you disapprove of and has taken up recreational marijuana use.
It is obviously difficult for you to meet your responsibilities for the moral upbringing and safety of your minor children if their adult sister is coming around and smoking pot illegally in your house. In order to defend your responsibility to your younger children and protect them and yourself from the consequences of illegal behaviour, you decide to set boundaries around what behaviours can take place in your home. You tell your daughter that you love her and know you can't make decisions for her, but you need her to leave her illegal hobbies at the threshold and not bring pot into your home or around your children. If she can't respect this boundary, then she can't visit, and will have to spend time with her younger siblings via phone or Skype instead. This is a reasonable defensive of natural boundaries.
Emotional hostage-taking comes in when you threaten to forbid your other children from having any contact at all with their big sister--even phone calls--until she ditches her boyfriend, goes into therapy with your buddy who will report back to you, and submits to random drug testing. Your intentions may be good. You may even be right that she would be better off. But you're still using your children and interfering with their independent relationships with one another in order to coerce an independent adult into ceding her autonomy and allowing invasions of her privacy and personal relationships.
That's not guarding boundaries. That's crossing them.
But isn't this what God does? Doesn't He withhold himself until we meet His conditions?
It can certainly feel that way, and I think this is a source of a lot of anxiety for Christians. We imagine God the Father as an authoritarian parent, withholding his love until we are good enough to deserve it.
Does that feeling of isolation and disconnection from God's love come from God--or does it come from us?
Think of our parent scenario again. In the first scenario, you tell your daughter that if she can't respect your boundaries, she can't come into your home. You tell her this because this is the only way you can fulfill your responsibilities to all of your children within your sphere. Outside that sphere, you cede control. You have limits. But inside that sphere, you have to take responsibility for the environment you foster for your children.
Now, maybe your daughter sees how reasonable this is and respects your rules. But maybe she doesn't. Maybe she thinks your standards are unreasonable and resents your boundaries. She might grudgingly go along with your rules but complain about them so much to her siblings that it poisons her relationship with them and with you. Or she might throw a tantrum and declare that she doesn't want to spend time in your house anyway, if you're going to be like that.
She feels like you are isolating her, and feels like you are choosing your arbitrary rules over a relationship with her. But is that true?
Sociological researcher Brene Brown writes and talks extensively about the role and effects of shame in our lives. One of the ways we often respond to shame--which she defines as "the intensely painful feeling or experience of believing that we are flawed and therefore unworthy of love and belonging"---is by discharging our discomfort and pain by placing it on someone us through blame. So the daughter who feels embarrassed and ashamed over the effects of her choices on her siblings discharges her shame by blaming her parents for making her look bad or making a big deal over "nothing." Rather than face her own responsibility for her actions, she externalizes her feelings of isolation and shame and projects them on to her parents: she feels bad, so they must be trying to make her feel bad. They don't really love her. They think she's a bad influence on her siblings because she isn't perfect. They have unreasonable standards for her that are making it impossible for her to be close to them.
Is any of this objectively true of her parents? Not in our scenario. In our scenario, her parents love her very much and long for a relationship with her. They'd gladly take whatever they can get---meeting up at a coffee shop or talking on the phone or cards in the mail. None of it will be rejected. They just can't let her cross this one line because they also love their younger children and owe them a safe, secure home.
The parallels with our feelings about God are, I think, pretty clear. Whatever we feel about being unable to partake of the sacraments because of unconfessed sin, or being uncomfortable in Church because of our consciousness that we aren't living as we ought, or even just going through a spiritual dry patch and resenting the effort of continuing to put in our part when it is difficult and unrewarding, that doesn't change the nature of Christ's love.
"For while we were still weak, at the right time Christ died for the ungodly. Indeed, rarely will anyone die for a righteous person—though perhaps for a good person someone might actually dare to die. But God proves his love for us in that while we still were sinners Christ died for us." (Romans 5:6–8)