Eternal Security can be defined as the believer's unbreakable relationship with the integrity of God. It remains unbreakable because of who and what God is, not who and what we are. It is what God does for us in salvation that makes this relationship permanent. Salvation is a gift of God and at the moment of faith in the Lord Jesus Christ, God gave us at least forty grace gifts that are irrevocable. He cannot and will not ever take these gifts away, ROM 11:29. We cannot negate them; no other creature can negate them; even God Himself cannot negate them, ROM 8:38-39. We are kept and guarded by the power of God, 1PE 1:5.
If you are an unbeliever, the issue is faith in Christ. You must be born again. ACT 16:31b "Believe in the Lord Jesus, and you shall be saved" JOH 3:17-18 "For God did not send the Son into the world to judge the world, but that the world might be saved through Him. He who believes in Him is not judged; he who does not believe has been judged already, because he has not believed in the name of the only begotten Son of God."
It is only through faith in the One who took your place on the Cross, and paid the price for your sins, that you can become born again and saved. Therefore, if you have never become born again and saved, take this opportunity to tell God the Father, in the privacy of your own soul, that you believe in His Son, the Lord Jesus Christ, as your personal Savior.