Yes we are in the end times and as for receiving the mark unknowingly I doubt God would allow that he would make it clear somehow im sure.
If we pick and choose scripture for our own liking, and reject other things written in God's word, we can very easily be deceived into anything.
Be not
deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap. Galatians 6:7
And he said, Take heed that ye be not
deceived: for many shall come in my name, saying, I am Christ; and the time draweth near: go ye not therefore after them. Luke 21:8
And if the prophet be
deceived when he hath spoken a thing, I the Lord have
deceived that prophet, and I will stretch out my hand upon him, and will destroy him from the midst of my people Israel. Ezekiel 14:9
Now the serpent was more subtil than any beast of the field which the Lord God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden? Genesis 3:1
Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: 1 Peter 5:8