Yo, it says we CAN DO all things, not that it'll be easy. And anyway, if you really think it's a joke, then say you have faith, you're raising a red flag for me. How can you say you have faith in God if you don't trust His promises? How can you say you have faith in God if you treat His Word with contempt?
You need to transform your mind. Stop thinking the way the world thinks.
Read Romans 12:1-2. And what is written below, an article I wrote on it:
To begin with in this article, a verse must be stated. Romans 12:1-2 (NASB, Greek only) reads: “Therefore I urge you, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, your spiritual service of worship. And do not be conformed to this world, but be transformed by the renewing of your mind, so that you may prove what the will of God is, that which is good and acceptable and perfect.” Another way to say that would be that you need to honor the Lord with your bodies, sacrificing what your flesh wants by transforming and renewing your mind, so you can know the will of God. So how exactly does one go about transforming and renewing the mind? Discipline and repetition has much to do with it. You need the discipline to say no to what is unwholesome, and the repetition of doing it over and over again to complete the renewing process- so that you have less slips into sin.
So what are unwholesome things should we discipline our minds to say no to? Lust, or desiring what is forbidden would be one thing. For example, if I knew by simply looking at something someone else has and admiring it I would desire it for my own (lust, commonly known as coveting), I would not admire said object. I would discipline my mind to say no to something that would lead it into sin. Looking at billboards with immodest people on them might be someone else’s weakness. By looking at billboards this someone would fall into lust of the eyes- also known as sexual lust. So, it would make sense for that person to discipline themselves to either not go where there are billboards to look at or not look at the billboards. It depends on where a person’s weakness lies.
Simply saying no one time will not keep you out of sin, however. You must keep the discipline until the weakness becomes a strength, or until you die and go to heaven. How do you keep the discipline? Reminder notes in areas of your living space, or on something you look at every day (like a computer screen or notebook) are a good idea. Finding someone to hold you accountable is also a good idea. What is to be done depends largely on the individual’s personality and needs. The biggest thing to keep in mind is that you are not alone- you have other Christians who care about you and want to see you grow, so seek them out and do not let their presence be in vain.