Free thinking is the rejection of religious influence in human life. You merely have to realize that priests, ministers and other religious con artists give no justification for their views, which are typically manipulative and degrading. Some may also reject all superstitious or supernatural beliefs, while others believe there may be something supernatural out there. All should reject claims that we must believe in, appease, or establish a "relationship" with such forces in order to be "saved" or benefited in some way. We see that humans are vulnerable to these beliefs, and believe it is up to us to speak out against them. Thus ?free thinking? can be thought of as living without superstitious attitudes and behaviors. ,
But isn't it arrogant to think that we are so great that we can do it all without God?
Yes, it is. Would that make you feel guilty for thinking that way? Why? Did your minister tell you it's bad to be arrogant? Is there a difference between a little arrogance (maybe really only confidence) and more extreme, self-centered arrogance? Must we always be at one extreme to avoid the opposite extreme? A little arrogance won't hurt you. Try it.
You can do your life all by yourself, with a little help from your friends.
Religion provides simple answers to questions great and small (usually the same simple answer). Free thought promotes Wonder instead. We should accept the lack of absolute purpose in living and see our responsibility as humans to search for the answers to all our questions, and create our own moral principles (for example, in the US Constitution.)
These principles are based on what we have left without gods; instincts and environment. Nature and nurture. Contrary to religious teaching, humans are not born bad. We are born complex. We do have selfish impulses, but we also want approval and acceptance from parents and others around us. The complex (and somewhat unknown) interactions between our impulses and our upbringing are what guides our morality, not original sin and covenants.
Nor do we need to be purified, cleansed, or in any way made perfect. We do not need to apologize for who we are or for the things we've done. Bad deeds can only be atoned for by trying our best to make up for them; no amount of apologizing to holy ghosts ought to make us feel any better.
Psychologists overwhelmingly reject religious models of human morality, and with good reason.
Geneticists overwhelmingly reject biblical creation theories. They find that we have a strong family relationship with primates, particularly the chimpanzee. The fact that our genes are almost identical with the chimps is confirmed by numerous labs using far more reliable tests than even a creationist judge would need to conclusively prove a paternity case in court.
For those who accept evolution: Is it likely that a creator would use an evolutionary process to create humans over hundreds of millions of years, and then fawn over us as his little hatchlings, only to sternly judge us based on how much we worship him?
When ministers make claims like these, and then add that it's sinful even to doubt these claims, it's your responsibility to stand up for yourself and doubt them anyway. Can anyone convince you of nonsense just by telling you your afterlife depends on you believing it?
Religions abuse your mind and your heart. You must have the courage to doubt yours.