The first of God's reasons seems to be "Be holy because I, the Lord your God, am holy" (Leviticus 19:1; Matthew 5:48). God made us to be like him. He is holy and perfect and he wants us to be holy and perfect. As a father he is holding himself up for his children as an example to be followed. And so his commands are about doing what he would do and not doing what he would not do.
The second reason would seem to be because his commands, his instructions, help us to get along with him, with ourselves and with others. Leviticus 18 - 20 expand on the 10 commandments. These chapters give details and no doubt answer questions that had arisen about following God's rules. They cover participating, or not participating, in the customs of the people around them, e.g., "Do not give your children to be sacrificed to Molech" (Lev 18:21). We mustn't defile ourselves or other people because it also defiles the land. "And if you defile the land, it will vomit you out as it vomited out the nations that were before you" (Lev 18:28).
For Reflection: There is nothing like the Bible for vivid imagery. God spoke of our actions defiling the land long before modern man came up with the idea of mankind polluting the land and the seas. Do any of these sins sound like fun? Do being disrespectful to God, ourselves and others sound like fun?
Let us pray. "May my tongue sing of your word, for all your commands are righteous." (Psalm 119:172).
Photo: "Streamerglass" by Tiffany Studios. Licensed under Public Domain via Wikimedia Commons http://commons.wikimedia.org/wiki/File:Streamerglass.jpg#/media/File:Streamerglass.jpg