Numbers 5:6 says “… if and of the people — men or women — betray the Lord by doing wrong to another person, they are guilty.”
Oftentimes we separate sin out into sin against God and sin against people. But we forget that people are image-bearers of God. He made them. And so when we sin against other people, we betray God. And by betraying God we are guilty of sin. Sin against God AND people! In a way sinning against a fellow image-bearer is actually worse, since it is offending TWO parties.
And unlike sins against God alone which require a sacrifice to cover the iniquity, sins against another person required more. The people had to give back what had been taken/cheated/etc (or its equivalent value) and add 20% on top. PLUS they had to get right with God.
What I’m saying is this: we’re going to mess up and hurt each other. But we need to go above-and-beyond to make it right. “I’m sorry” is necessary but not sufficient. We need to repair, replace, or recover. And then, once we have made it right with our brother or sister, then we can come before God to ask for forgiveness. It’s hard to grant forgiveness to someone who has not made a serious attempt to rectify the wrong.
You’ve gotta make it right before you can make it right.