You may be correct. I tell you what if you can give me one example of how we miss Gods mark. I'll buy it. Otherwise sin is just some indefinable thing that is whatever we decide it is. If we start making the rules insread of God. Doesnt that make us God?
Sin is anything but indefinable, in fact, the Scriptures are very clear about what is sin and what is not sin.
Romans 3:23
For all have sinned, and come short of the glory of God;
John 8:31-34
Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed;
And ye shall know the truth, and the truth shall make you free.
They answered him, We be Abraham's seed, and were never in bondage to any man: how sayest thou, Ye shall be made free
Jesus answered them, Verily, verily, I say unto you, Whosoever
committed sin is the servant of sin.
Galatians 3:22
But the scripture hath concluded
all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
We miss God's mark whenever our action -- preceded by our decision -- was not motivated by His Glory.
And here is the kicker: Since we were born with 'self' on the throne, we will continue to be motivated by selfishness, even when we think we are doing a charitable action, which is a good thing in itself.
In 2 Corinthians chapter 2, the Apostle Paul contrast the "ministry of letter" vs the "ministry of the Spirit" the former gives out death, the latter gives out life.
Only through Spiritual growth can we start to not miss the mark as often, or as severely. And when we are mature in the Spirit, sin will no longer be attractive to us because we now are fully committed to our new Master, whom we learn to love.
You asked for examples, here is one:
I wake up in the morning, realize that I still didn't get a call from that sales lead whom we had tried so hard to engage for the past six months.
Option #1. I could see this as an opportunity to trust in God's plan, one more day.
Option #2. I could start to doubt and question God's faithfulness.
Option #2 is a sin, not because I steal, envy, or murder, but because my decision is to question God despite what He had provided me with in the past. My decision is motivated by selfishness.
This is an example on why we can't escape sin. Because sin is not only behavioral, but also mental attitude. And without God's help through His Son's sacrifice on the cross, we have no hope whatsoever.