It can be very difficult in today's world to remain pure, be good, and avoid the temptation to sin. Sin is all around us and much of that sin is attractive to most people. The devil knows how to tempt us.
See blow for some ideas to remain pure and resist temptation
Alot of people believe that something that does not hurt anyone can't be a sin. But that is not correct. A sin is something contrary to God's will that separates you from God. God created us and knows what is best for us - just as we know what is best for our children. We are as children to God. No matter how advanced our society becomes, we will never understand everything nor can we reason how something will effect the future. But God knows everything. And He gave us rules to follow to keep us safe and to keep society functioning and safe. When we violate his rules, we separate ourselves from him. He still loves us and is ready to help us, but we become blinded to him due to our sin. For example, premarital sex between two consenting college students. They believe they are not hurting anyone - and true they are not hurting any human. But that act is contrary to God's will and if we instead follow his will things will go better for us. So sin is NOT defined by hurting another person or not. Some things can be a grave sin even though they do not hurt anyone.
Because of all the negative influences that we have been surrounded by on TV, in the lyrics of the music we hear, and in the news, and even from our peers - we begin to believe the devil's lies and we begin to think that some actions and thoughts are OK because they "feel good", or they make you look cool, or it does not hurt anyone so how can it be bad. But these are the devil's tools to trick us. Many things "feel good" that are not good. How something feels is not a good measure for if it is acceptable to God. And some things that do not hurt anyone is hurting us - hurting our soul - separating us from God. A sin is something that separates us from God - it may not hurt anyone else, but it damages our relationship with our Lord because the our sin saddens God. Most sins do hurt other people - and they are easy to understand as sins. But some sins ONLY HURT THE SINNER and those are harder to see as sin because Satan has convinced us that if our actions do not hurt anyone else, then they are not sins. This is NOT TRUE. Some sins simply hurt ourselves and our relationship with the Lord.
From an early age, we see so many bad and impure things on our TV's - such as college students having fun partying and have indiscriminate sex. The TV portrays these things as acceptable and, of course, enjoyable. If we continue to watch these shows, listen to music with similar impure lyrics, or read books that portray such things, then over time these bad things "become normal" to us and we eventually no longer see them as sins. And this pulls us away from our spiritual life and distances us from God because He cannot be with sin. Remember, sin is anything that pulls us away from God and hurts our relationship with Him. And He has set the rules because He knows what is best for us. And He knows what harms and corrupts us - so he has given us rules to protect us. We are his children, and as children, we do not get to set our own rules. Would you let your child set their own rules? I don't think so!
Our souls know what is right and what is wrong - God has given us the Spirit to direct us. We just need to practice listening to that little voice that is the Holy Spirit. The Spirit guides us and directs us and protects us - but we need to practice listening and trusting the Holy Spirit. The Holy Spirit works through or conscience - so if something does not "feel right", you should stop, pray, and think about it. Discerning the will of God is not always easy but start trusting Him and speaking to Him often and practice listening. The Spirit often "whispers" so you need to listen. The more time you spend with God and speaking to him, going to Mass, listening to, or watching, things that speak of or portray Christian values then the more you will draw closer to God and you will learn to discern what is right and what is wrong. So trust Him, spend time with Him, and listen for His quiet voice that is our conscience.
As humans, when we are exposed to something over and over, it becomes attractive, acceptable and normal to us. So the media that is exposing us to indiscriminate sex, lying and cheating as ways to "get ahead", enjoying drinking and doing drugs, and being unfaithful to God in many other ways - is harming us and changing us on a subconscious level. We need to consciously make an effort to pull away from these negative and evil influences - they are the tools of the devil. It is OK to watch TV and, today it is nearly impossible, to find any show without some nudity or bad language, but you just need to pick shows, music, and books that are less offensive. And on a conscious level realize that what the show, music, or book is portraying as acceptable behavior is wrong - don't fall for the devils lies. Remember that what we choose to watch and listen to for enjoyment, influences our thoughts, opinions, and actions. If those things are impure, it will sink in and on a subconscious level it will change us and separate us from God.
As an analogy, the quality of the ingredients that go into a recipe, and how you follow the directions, can either make the meal taste great or horrible. If you put in the correct and best ingredients and you follow the recipe directions, then the meal will be great! But if you put in rotten ingredients or don't follow the directions, then the meal will be horrible. The Bible is the recipe book and the Church helps us to understand and interpret the Bible. So follow the directions and put in your best effort! In order to know the recipe, you need to go to Church, at least weekly, and speak to God daily. Bring Him into your life as you would a spouse or a best friend. Speak to Him as you speak to your friends and family. Let Him into your life. You can also watch some good programs on family friendly channels - such as the Hallmark channel, or on Christian stations and listen to Christian music and Christian radio. These are all good ingredients - choose to use the best!