Sin is when we do things our way instead of God’s. It gets in the way of relationships, and means our friendship with others and our friendship with God, suffers.
For example…I tell my best friends secret to someone else, and lots of people find out. My best friends really upset, and our relationship is a bit broken by that. I’ve let God down too as I’ve done something that he wouldn’t like.
But, what if my Mum asks me to visit my Gran, or an elderly family friend on the way home from school, and I go shopping instead? My mum doesn’t know I didn’t go, and my Gran wasn’t expecting me anyway. They may never find out what happened.
Yep, because even if neither of them find out, I still know that I’ve ignored my Mum and so our relationship now has a lie involved, and won’t be as good because of it. Gran also missed out on an opportunity I had to love her. As for me and God… it effects us too, because again, I’m doing things my way, not his.