The Him is Jesus Christ. Jesus was God, is God, will forever be God, however, he had to be made into the form of man to come to earth. So, yes, God made God. God being triune, (three-in-one) this is possible and it truly happened.
Was Jesus sin? Personally, no! BUT go back to the Law of the two goats, where one is sacrificed for the sins of the nation that entire year and the other one everyone laid their hands on to take on their sins, before it was let loose and kicked out of the nation.
That was a shadow of what Jesus did. He who never sin, took on all the sins of his people. All of them. So, yes, he was sin. Nothing much left of him at that moment except for sin, so he was sin.