Religion is inimical to Christianity being based on outward performance rather than inner transformation. The Greek translated ‘religion’ is ‘threskiah’ which means ‘observance’.
Christianity is simple: We are all born sinners and unable to help ourselves, so God sent his Son to take the penalty our sin deserved, delivering us from the power of sin, death and the devil. Religion says, although born sinners if we can just work hard enough we can justify ourselves before a holy God.
Religion is from the Master Counterfeiter himself. Or as 2 Corinthians 11:14-15 says: ‘Did not even Satan marvellously transform himself into an angel of light? Therefore it is no great thing if his ministers also transform themselves as ministers of righteousness, whose end shall be according to their works.’
James 1:27 says, ‘Pure religion and undefiled before God and the Father is this, to visit orphans and widows in their afflictions, and to keep oneself unspotted from the world.’
'Doctrine' means 'teaching' and Jesus was a 'rabbi' which means 'teacher', hence Christianity is founded on Jesus' teachings. However, much so-called 'Christian' doctrine arose from the desire of secular authorities to seize control of Christianity. When Constantine made Christianity the official religion of the Roman Empire, what had been a vibrant but persecuted sect became a state-sponsored career path for ambitious time-servers.
Before Constantine the Church determined doctrine and the State administered judgement. After Constantine the reverse pertained, resulting in travesties far removed from Christianity, like the Crusades, the Holy Inquisition and the bonfires of the Reformation.
Paul said in Acts 26:5, ‘…according to the strictest sect of our religion I lived a Pharisee.’ And in James 2:19, the apostle sarcastically observed: ‘You believe that there is one God, you do well; even the demons believe and tremble’.
Jesus challenged the Pharisees in John 8:42-44 “If God were your father, you would love me, for I went forth and came from God; for I did not come of myself, but he sent me. Why do you not know my speech? Because you cannot hear my word. You are of the devil as father, and the lusts of your father you will do. He was a murderer from the beginning, and did not abide in the truth because there is no truth in him. When he speaks a lie, he speaks of his own, for he is a liar and the father of it.”