You will say it. Yes, you will. Everyone will.
The best way to say it is now, whilst you are alive drawing breath, whilst you can repent and turn back to Him through Jesus Christ.
How truly terrifying it would be, if, when you spoke those words, out of your own physical resurected lips, you were facing judgement after years and years of life (and hell), hardening your heart and closing your ears to the Gospel, rejecting Him and His free gift.
So horrific I don't even want to contemplate it. Pointlessly.
And crazy, just crazy. Why would you choose that?
Jesus Christ is God. You will say that one day. An absolute guarantee.
The question is: will you say it to your Saviour, or to your Judge?
Up to you.