Many people think that because Jesus died for our sins, we have the free pass to sin, or that if we don't sin, Jesus died for no reason. That's garbage for several reasons.
People are natural born sinners. Nobody can go without sinning -- no matter the amount of effort. Of course, Christians love Jesus, so they don't want to sin, but that doesn't mean they won't make mistakes. Accidents happen, however, "Well, I'm just going to sin inevitably, so I might as well do what I want," is not an excuse.
Comparatively, I have a case on my phone, but that doesn't mean I purposely throw my phone at the concrete just because I can. When Jesus died, He paid for all sins, but, because we love Him and value Him, we don't want to throw Him onto the concrete for no reason. That's not just abuse of His sacrifice, but it's manipulative and takes complete advantage of what He did for us.
Sinning actually harms us. God doesn't call things sin because He's a taskmaster or stickler. Things that God calls sin are to protect ourselves and each other. Every time we commit sin, it not only damages our own minds and bodies, but it puts a damper on our personal relationships with Jesus, since, by sinning, we thereby put our personal desires above God.
Every time you betray a friend, that bond between you and that friend weakens. Jesus obviously always refreshes us and forgives us when we repent, so that's a little different than a human friendship. Looking at it from a new perspective, Jesus never did anything bad to us to deserve betrayal; He's the most forgiving friend someone could ask for. He doesn't pull away from us when we mess up, but let me ask this: If your best friend were as perfect as Jesus, would you purposely, repeatedly do him/her wrong just because you could?