Being filled with the Holy Spirit and baptized in Jesus' name, standing for your beliefs no matter what, doing God's will and reading His word/praying/worshipping Him, and doing everything you can to live for Christ
A true Christian lives by faith in the resurrected Jesus.Despite the wide variety of beliefs that fall under the general "Christian" label today, the Bible defines a true Christian as one who has faith in the death and resurrection of Jesus Christ, who has the Holy Spirit residing within, and whose life evinces change consistent with faith in Jesus. Read more: http://www.gotquestions.org/true-Christian.html#ixzz2OD7l00pj
There are a few things that make one a TRUE Christian:
1. One accepts God's Word, the Bible, as truth. -John 12:49; John 17:17
2. One is no part of the world, as Jesus was, neutral in political and social conflicts. -John 18:36
3. They have love amongst themselves. -John 13:34,35
4. One makes Jehovah's name know. -John 4:16-21
5. They preach about the good news of the kingdom.-Matthew 24:19,20
To find out how the first century Christians measured up to the requirments for true Christianity, as well as who is following that pattern today, I invite you to follow this link and read the March 2012 edition entitled "What are the Marks of True Christianity?"
I'm no Christian, but from what I've seen in others the main things that make a true Christian are blind hypocrisy, a fanatic obsession with ridiculous rules, and of course a stubborn ignorance that can't be reasoned with, no matter what.
There are a number of things that identify someone as a true Christian. One of them is recognizing Jehovah God as the source of life. Psalm 36:9 says "For with you is the source of life; by light from you we can see light." As we recognize God as our Creator and the source of life, as true Christians we have to show respect for life. This means to abstain from blood (consumption, blood transfusions) and also to cherish life (anti-abortion).
This also means that we should follow his commandments. Do not murder, do not steal, do not worship idols, etc.