Let me give you a scenario:
For any vice, you want to stop it, but you are convinced that it is impossible to ever stop it are you surrendering to an evil or extending it, or are you just being reasonable?
Also is it bad in the same way if you think that it could be stopped in the future but not now?
"And Jesus looking on them, saith: With men it is impossible; but not with God: for all things are possible with God. " Mark 10:27
some vices felt impossible to overcome before i really got into my faith, and really, since i was not seeking Gods help, it was impossible for me, because, as i was just saying in your other post, alone it is impossible, but with God we can do all things.
“I can do all these things in him who strengtheneth me.” Philippians 4:13
it does take time to become detached, but you do not have to sin even if you feel a great pull from the temptation, all you need to do is pray that God will give you the grace to overcome your temptation, and then by His grace, get yourself out of there however you can, which God will show you…for example, if you are tempted to lustful thoughts, and you are just laying in your bed not knowing what to do…well you have to get out of bed and go wherever you can to get your mind off of it, you cannot stay where you are and just lay there motionless, Gods grace will motivate and prompt you, but you must move your body to get out of there.
or i’ll put it the way Fulton J. Sheen says, we are like cars, and Gods grace is like gasoline, God will feel up your tank, but you still have to drive the car!
well, to answer your question, if you are convinced it is impossible to stop committing a vice, then no you are not being reasonable, because that is contrary to the truth,
and instead what you are doing is falling for a trick from the devil, who knows you do not take the proper defense against your sins, and that you give up easily.
what you would need to do in that scenario, is ask for advice from a good priest, and then take that advice no matter what you think of it,
and yes, it is bad if you think it could be stopped in the future and not now, because that’s just putting it off, there is never a good excuse to live in sin, there is never a person or thing or place or job that makes it impossible not to sin, the only thing that makes it difficult is when you decide you don’t want to give something up which leads you into sin, simply because of how it benefits you in some temporal way, and you choose that over pleasing God…which is a sin against the first commandment, and basically what that is, is not trusting that God provides…we seem to forget that God is the one who takes care of us, and if you put your trust in something other than Him to provide for your needs, then you will really be worse off, but if you abandon the things that lead you into sin, then God will bless you and take care of you…
we try so hard to survive this life, but how hard do we try to save our souls to survive in the next life? of course surviving in this life is very important…but too many times we lose sight of the goal, and we forget that God is really in control, not our jobs, or our money, or our government, or anything else, but only God…
does that help?