The issue is not whether or not you KNOW that there is "ONLY ONE GOD IN ALL OF EXISTENCE", for such a fact CANNOT be denied.
You believe that there is one God. You do well. Even the demons believe—and tremble!
James 2:19 NKJV
It is also an illusion that any man can "accept Jesus into their heart"or "make Jesus Lord of their life". Jesus IS LORD over EVERY life, WITHOUT exception. Is what does happen is that the regenerate person is changed, and he glorifies God as God. Herein is the line drawn between the elect and the reprobate, between salvation and abiding under God's wrath.
For since the creation of the world His invisible attributes are clearly seen, being understood by the things that are made, even His eternal power and Godhead, so that they are without excuse, because, although they knew God, they did not glorify Him as God, nor were thankful, but became futile in their thoughts, and their foolish hearts were darkened.
Romans 1:20-21 NKJV
What then does it look like to glorify God as God?!
Sacrifice and offering You did not desire; My ears You have opened. Burnt offering and sin offering You did not require. Then I said, “Behold, I come; In the scroll of the book it is written of me. I delight to do Your will, O my God, And Your law is within my heart.”
Psalms 40:6-8 NKJV
This is the work of God alone as Jesus is manifest in our lives through the indwelling power of the Holy Spirit. This is what "the remission of sins" looks like.
