Well it is a fact. No one is perfect. At least, no human being is. But is it a bad thing to make it a goal in your life to be perfect? To do your best to be upright? I don't think so. IF you are aware that you will never be able to do it on your own.
If you try to be perfect, you will soon realize that you are not. If you think that you have reached perfection, then it means you have never been further from it. But if you want to be perfect, you have to know that first, you need to be saved.
To the question "How to be perfect" I have to answer "Once you're saved, you'll have everything you need to be perfect". But then again you might only reach perfection in heaven. Or should I say you will.
Then you might want to ask how to be saved. I will then answer "It is all explained in the Bible : you have to recognize and confess that you have sinned and that it seperates you from God. God is Holy, you are a sinner. Then you have to realize and confess that Jesus Christ(the Son of God, that is to say, God Himself) has come to earth to live as a perfect man without sin, then die on a cross instead of you as a perfect sacrifice to reconcile you with God and He rose again three days later(as He promised) because He won over death and sin and went back to heaven. He promised and will return just as he left to reign forever on the earth. Now all you have to do is to believe that, say that you believe it, and live by it. Which means repent from your sin(turn away from it) and trust God who will give you the Holy Spirit that will allow you to love God with all your being and others as yourself and hate sin and depart from it. You will have eternal life and have a relationship with God. You will then be able to obey His commands and start your journey to become more and more like Christ. Jesus Christ will be your Savior and Lord." (if you have more questions, ask me or have a look at this website)
So, once this question answered and this decision made, there is no excuse left not to do your best and get closer and closer to perfection each day. So, when someone tells you "it is not honest to do that" or "it's wrong to do that" or whatever that challenges you to change for the better, never, never NEVER EVER EVER answer "No one is perfect!". Instead, recognize that you have been wrong, ask God to forgive you and change what has to be changed. He will help you. I promise.
"Be ye therefore perfect, even as your Father which is in heaven is perfect."(see Matthew 5)