II Corinthians 6:18: And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
Paul was writing to the believers in the church at Corinth. They had a lot of mess to clear from. They were still living in worldly passions and desires. They were probably still having unwanted relationships, very carnal and following their own fleshly desires. Paul thought that they had to be taught the basics of living a life filled with faith and holiness to God.
There are certain values and standard of life that every child of God needs to adhere to. If we live a life that brings honor to God, He will be a Father to us and we will be His children. When we are set apart to serve God, it is expected of us to live a life of separation from worldly passions and desires. God hates it when we worship anything other than Him. He cannot stand the worship of statues or anything that is assumed and made to look like Him. Darkness has no association with light just as much as the devil does not associate with our God. We have to leave behind everything that hinders our walk with God. It will do us good if we identify and put behind us everything that is blocking our relationship with the true God.
When we wilfully give up everything and anything that stands as a hinderance between us and God, He will accept us as His children and will be our Father. He will save and protect us from the deadly schemes of the devil.