One notices that the OP never condemns members of any other group that do not follow to the letter every guideline of the group. Only Christians.
One also notes that Christians, being fallible human beings, fall prey to temptation and fail to live up to God's standards.
One also finally notes that Christianity is not religion, it's relationship. Many, however, who claim the name of Christ do so as religion, not as relationship, hence they can't get it right. It is beyond obvious that those who do not even claim the name of Christ are simply incapable of understanding it. Take this test.
You are about to be married. On the day of your wedding, you approach your spouse and say, "Give me a written list of rules which you expect me to live by so I can demand your acceptance. I will spend my entire life trying to add qualifications to them, twist the meanings of their words, and get as close to the line as I can, so that I can plausibly claim I lived up to them. Thus, I can demand that you accept me and not leave me". What do you think the reaction would be? Of course you would not do something so stupid. If you actually love your spouse, you instead watch them, listen to them, pay attention to what they like and dislike, and thus demonstrate your love through your actions. If you mess up, cross the line and hurt your spouse, you apologize and try never to do it again. You don't NEED a written list of rules. That's the difference between religion and relationship. Those who want to live their lives as they please, thinking that God will accept them no matter what are fooling themselves. Those who live in relationship with God, OTOH, do not live by a bunch of rules, they seek every day to please God. When they sin, true repentance follows. Remember this:
21 “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven. 22 Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name and in your name drive out demons and in your name perform many miracles?’ 23 Then I will tell them plainly, ‘I never knew you. Away from me, you evildoers!’
What matters? Whether He knows you. You can do all kinds of nice things and it won't matter at all if you don't have a relationship. And if you have relationship, you don't think "I can get away with anything", you think "How can I please God?". You wouldn't do that to your spouse, why would you do it to God?