If any form of life on this planet's life is set, why did god create those that are against him?

He didn't create people to be bad, but we are all imperfect and have free will to choose how we want to live our life. He made satan - but when he made him he was an angel in heaven with God. Satan chose to leave the love of God and wanted the glory for himself. God does not control our actions we all make decisions for ourself, and will have to suffer the consequences of our actions.