31He then began to teach them that the Son of Man must suffer many things and be rejected by the elders, chief priests and teachers of the law, and that he must be killed and after three days rise again. 32He spoke plainly about this, and Peter took him aside and began to rebuke him.
33But when Jesus turned and looked at his disciples, he rebuked Peter. "Get behind me, Satan!" he said. "You do not have in mind the things of God, but the things of men."
34Then he called the crowd to him along with his disciples and said: "If anyone would come after me, he must deny himself and take up his cross and follow me. 35For whoever wants to save his life[c] will lose it, but whoever loses his life for me and for the gospel will save it. 36What good is it for a man to gain the whole world, yet forfeit his soul? 37Or what can a man give in exchange for his soul? 38If anyone is ashamed of me and my words in this adulterous and sinful generation, the Son of Man will be ashamed of him when he comes in his Father's glory with the holy angels."
Mark 8.31 - 38 (NIV)
The "things of men" are the things that do not reflect the gospel of God's grace. These are the things that occupy our hearts and minds for self pleasure and enjoyment which do nothing to point our hearts back to Jesus. They can be as sedated as frivolous thought or extreme as blatantly popular spirituality - anything which obstructs or distracts us from attributing our existence to God's grace, faithfulness, mercy, love, holiness, perfections, etc. . . . those things we must avoid like the plague. "Those things" are the hybrid false idols of our age. Again, if Jesus Christ is not our starting point, wherever we attempt to head towards will only gain distance between us and God.