I have much trouble with this, and I wonder if anyone can relate.
I find that I often make up a God in my head, and pretend that he's Jesus Christ. This God is cool with things like masturbation and pre-marital sex, because he doesn't care. He's all about love and good feelings. He changes with the times and is pretty much just there for when his followers need something or are in trouble. He condemns hate of all kinds, including hateful Christians who would condemn "sins" that are perfectly fine according to science and this loosy-goosey type of religion.
Then, I contrast that with the God who is Jesus Christ. The God we find at the creation of the world, and the creation of ourselves. The God who is present and fillest all things, with a rod and staff that comfort His followers forever.
I'm afraid that I get the God I've made up, and the God who is really there in the Chalice, confused sometimes. I will be about to sin, and then I'll think "Well, the god I know and follow is fine with this. Let the religious nutts have their strict God. My god doesn't mind me sinning."
This has been an extreme stumbling block for me as of late, and I think it's due to my time in another more "liberal" Church. Being back in Orthodoxy, I still have this voice in my head that tells me it's okay to sin, because we have to make God fit the times and such.
When I try to follow God, the true God, this false god gets in my way. My confesser tells me to regularly pray my rule and to attend Church and experience the true God, Jesus Christ, and learn His will. I am instructed to read the scriptures and listen to His commandments.
Does anyone else struggle with such a thing?
Sure. Regardless of background, most of us struggle with the projections of a prideful ego one way or another in our conceptions of 'God.' Some are perhaps more prone to conceive of a perpetually angry, judging God, while others are more prone to accentuate God's merciful aspect to such an extent that the commandments are rendered nearly useless. But both stem ultimately from the same rotten root of pride. The only medicine for this, truly, is the experience of God's grace, but for this to take effect continual repentance is needed.
References elude me, but I recall many teachings from the holy ascetical Fathers that the devil will accentuate God's mercy and forgiveness when he is tempting us with sin in the form of pleasure, only to cast us into despair once we have succumbed to the same temptation, by suggesting that God now regards us sternly and will not forgive us for having sinned. Our experience certainly bears this out.
Perhaps the best way of thinking about it for the time being is to reflect on your experience with sin: How does it make you feel once the pleasure of the sin has subsided and your conscience reasserts itself? I generally find I will feel degraded, and robbed in some manner of my integrity as a person and will feel negatively about myself for having allowed it. I felt this way long before I had any conception, theological or otherwise, of sin qua
sin. I would be surprised if you felt differently. If that is the case, when you are being tempted, try to remember how you will feel about yourself after having sinned... depleted, shameful, guilty, full of self-loathing and possibly despair. This places the emphasis on your responsibility to yourself
and your existential condition, regardless of how you are thinking or feeling about God at the moment. Even the pagan Stoics, for instance (and I here abstain from making any reference to the rather different metaphysical assumptions which admittedly undergird their ethics to a great extent) were able to maintain very strict standards of virtue by simply relying on their observations of how behavior impacts psychology in a more or less beneficial or disruptive way.
Hope this helps.