Many Christians today can't be called a true believer because of there lifestyle. Your lifestyle tells a lot and the type of Christian you portray is what people around you that Christianity to be.
1Timothy 4:12 AMP
Let no one despise or think less of you because of your youth, but be an example (pattern) for the believers in speech, in conduct, in love, in faith, and in purity.
Once you decide to follow God, the way you live your life is important because it can lead people to God and it can lead them astray. As a child of God, you must be mindful of how you live your life.
The moment a non-believer sees how you behave, he or she will conclude that that is how believers behave. Be careful of what you do and how you do things at home, work, society and everywhere you find yourself.
Stop bringing disgrace to God and stop blocking others that want to come to God through your lifestyle. The way you live your life matters a lot to the Salvation of others. So, as stated above in 1Timothy 4:12 , be an example of a believer that glorify God in speech, in conduct, in love, in faith, and in purity.
Remember, what people think of your faith and your God is determined by the way they see you.
Once again, meditate on the question - What type of believer are you?
Shalom.