Your question,as been said before, is a loaded question.The answer is Yes and No.Yes you can express yourself to GOD and No it does not mean you are approved by GOD.GOD has requirements... Let me explain.
GOD deeply cares for us.(when I say GOD,I Mean Almighty GOD mentioned in Genesis 17:1,Psalms 83:18,Isaiah 42:8, see Green's Literal Translation for these scriptures,in this forum.)GOD wants us to benefit from his loving direction. If we worship him in the right way, we will be happy and will avoid many problems in life. We will also have his blessing and his help. (Isaiah 48:17) There are, however, hundreds of religions that claim to teach the truth about God Yet, they differ greatly in their teachings about who God is and what he expects of us.
How can you know the right way to worship God? You do not have to study and compare the teachings of all the many religions. You need only learn what the Bible really teaches about true worship. To illustrate: In many lands, there is a problem with counterfeit money. If you were given the job of picking out such false money, how would you go about it? By memorizing every kind of counterfeit? No. Your time would be better spent if you studied real money. After you knew what real money looked like, you could recognize a counterfeit. Similarly, when we learn how to identify the true religion, we can recognize those religions that are false.
It is important that we worship God in the way that he approves. Many people believe that all religions are pleasing to God, but the Bible does not teach that. It is not even enough just to claim to be a Christian. Jesus said: “Not everyone saying to me, ‘Lord, Lord,’ will enter into the kingdom of the heavens, but the one doing the will of my Father who is in the heavens will.” To have God’s approval, therefore, we must learn what God requires of us and do it. Jesus called those who do not do God’s will “workers of lawlessness.” (Matthew 7:21-23) Like counterfeit money, false religion has no real value. Even worse, such religion is actually harmful.
God gives everyone on earth the opportunity to gain everlasting life. To have eternal life in Paradise, however, we must worship God properly and live now in a way that is acceptable to him. Sadly, many refuse to do so. That is why Jesus said: “Go in through the narrow gate; because broad and spacious is the road leading off into destruction, and many are the ones going in through it; whereas narrow is the gate and cramped the road leading off into life, and few are the ones finding it.” (Matthew 7:13, 14) True religion leads to everlasting life. False religion leads to destruction. God does not want any human to be destroyed, and that is why he is giving people everywhere an opportunity to learn about him. (2 Peter 3:9) Really, then, the way we worship God means either life or death for us.
So, you see, we can not do our own thing, or do what ever we want and expect no consequences for it.
So, Yes you can worship GOD your own way, if your own way is in harmony with the will of GOD.No you can not, if you Isolate yourself.For GOD wants you, after discovering the truth about him, to encourage your fellow brothers and sisters.Hebrews 10:24,25