The main problem with arminianism, the doctrine that man is the sovereign decision maker in regards to salvation, is that it makes the omnipotent God of all reality, a colossal failure.
The sanctification work and intercessary prayers of the Holy Spirit is a failure.
The promise of Jesus not to leave or forsake the sinner becomes a broken promise.
The payment for the sins of the sinner by Christ is acceped by the Father, becomes rejected.
The intercessary prayers by the Son are failures.
The Son, whose very purpose for becoming incarnate, is a failure, as He ends up not fulfilling everything that the Father sent Him to do.
The Son becomes not being able to please the Father.
The Father's plans that were created while having all knowledge become worthless as He is not able to accomplish the things that He not only wants but set out to achieve.
For Jesus to be God, all of the above must be false and therefore arminianism is also false.
If arminianism is true, then the God of the bible must also be false as He is not omnipotent, omniscient, trust worthy, and able to save people to the uttermost.
That is all.
