Of course it is. Even without the Scriptures no man is without excuse because the world and all of life attest to the sovereignty of the Triune Creator of heaven and earth.
The fact remains, however, that God does not give all men eyes to see or ears to hear or a new heart with which to believe. If He did, all men would believe and be saved. And obviously, they're not.
All men do what they want to do. The natural man has not been given the ability to know the things of God, and therefore he willingly refuses to believe, according to his fallen and corrupted nature. Those whose minds have been renewed by the Holy Spirit, according to the will and purpose of God, will understand and believe the truth of the risen Christ.
But ye believe not, because ye are not of my sheep, as I said unto you. My sheep hear my voice, and I know them, and they follow me: And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand." -- John 10:25-28"Jesus answered them, I told you, and ye believed not: the works that I do in my Father's name, they bear witness of me.
You do not know if that is true. That is a conclusion based on your persal biases.
If He did, all men would believe and be saved. And obviously, they're not.
Does man not have the ability to choose to believe or not believe? Ever hear of free will?
That's not scriptural.