One thing to remember is that Christian's are saved sinners and that they still sin. The change is in their relationship to sin and how they now view sin. No Christian is perfect and they will not be perfect until they are in Heaven.
A persons relationship with sin changes as they have a deeper relationship with God. They desire to become more like God or as some also say, more like Jesus Christ.

To understand what it means to be a Christian one should not look at man/woman but to the Bible. Yes we can look at others to see how they act but as I have said Christian's still sin and if we build our faith on them then we will be disappointed. That is why Christ says "follow me" Christ at no point says "yeah listen to me but after that go follow x y z".

As you grow in faith by following Christ's example, your own life will take on a new meaning and before when you were blind to the things of God your eyes will be opened to them.

We all sin but we desire not to sin. God will give you the grace you need to fight sin.