Believe it or not the above question has an incredibly simple answer, but the things you have to understand to grasp it are not so easy. Let us start with a question.
“In this the children of God and the children of the devil are manifest: Whoever does not practice righteousness is not of God, nor is he who does not love his brother. For this is the message that you heard from the beginning, that we should love one another, not as Cain who was of the wicked one and murdered his brother. And why did he murder him? Because his works were evil and his brother’s righteous.” 1 John 3:10-12.
“Then God said, ‘Let Us [Father, Son, and Holy Spirit] make man in Our image, according to Our likeness; let them have dominion over the fish of the sea, over the birds of the air, and over the cattle, over all the earth and over every creeping thing that creeps on the earth.’ So God created man in His own Image; in the image of God He created him; male and female He created them.” Genesis 1:26-27.