We sin because we have free will. True?

I have just watched:
https://www.youtube.com/watch?v=t9k-oO9TOUg
An arminian says that sin is something against the will of the Lord, so how would the Lord decrees or makes it happen? It makes no sense: the Lord makes a creature sin and punishes it. Therefore, we sin because we have free will.
Is it true?
The Christianity believes that here on earth, just one Just lived: Jesus. All others are sinners.
If we have free will, would not be possible to happen that someone would not sin?
We believe that there was no just and never will be except Jesus.
If there is free will, how can we declare this absence of just men?
We sin because we are naturally departed from the Lord and we are locked on sinning. Sin for a human is like the law of gravity that was established by the Lord. Although, sin is against the will of the Lord, it will happen to anyone detached from Him; because He established so. The Universe is governed by natural laws and natural behaviors. In some way, the Lord makes a man sin, due to this natural law, common to all humans.
The supernatural is a man pleasing the Lord. He needs a divine intervention, a touch from Jesus, to be purified.
The Lord is not confined to our Universe and our time. The universe will flow according to the natural laws. Men are like fishes in a aquarium and can not escape it, but some men were chosen to see the Creator thanks to a break in the natural law that was accomplished by Jesus. He died so that I could live. He made a miracle happen on my life.