The Bible Makes it very Clear about how know for sure that your saved
"Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:" (Romans 5:12)
When Adam and Eve sinned in the Garden that sin nature has been passed down from dad to son every since then, and always will.
I have 3 young children and when my middle daughter was caught drawing on the wall at 4 years old and confronted about it, she lied. No one had to teach her to lie, it was already in her.
"For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord." (Romans 6:23)
God Tells us that because we have sinned we are due death.
This death is refering to our eternal resting place. You see because we have sinned what we deserve is Hell.
The Bible tells us of how Hell is a literal place with a fire that never stops. Pain that is everlasting.
And according to this verse thats where we deserve to go, but the Gift of God is eternal life through Jesus Christ our Lord.
"But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us." (Romans 5:8)
He Himself came down to earth and took on the rob of flesh and called himself man. He lived a sinless life and on Calvarys Cross he paid the price for all of our sins.
"And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross." (Philippians 2:8)
"That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved." (Romans 10:9)
"For whosoever shall call upon the name of the Lord shall be saved." (Romans 10:13)
Your Salvation isn't dependent on the words of a prayer. God Knows the intent behind our prayers.
"Search me, O God, and know my heart: try me, and know my thoughts:" (Psalms 139:23)
So if he knows our thoughts and our hearts, He knows if we truly believe and if we truly desire him to save us.
If you know that your a sinner on your way to hell, and believe that Jesus died to pay the sin debt of the world, and that he rose again the third day, Its time for you to call on God to Save you.
Today is the Day of Salvation!
"Be it known unto you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead, even by him doth this man stand here before you whole. This is the stone which was set at nought of you builders, which is become the head of the corner. Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved." (Acts 4:10-12)
Whether you decided to put your faith in the Lord or if you decided you werent ready, you made a decision!