The same Savior who said, "I give unto them eternal life and they shall never perish" (Jn. 10:28) also said, "Strive to enter by the narrow door; for many, I tell you, will seek to enter and will not be able." (Lk. 13:23-24)
The same apostle Peter who said, "In his great mercy he has given us new birth . . . into an inheritance that can never perish" (1 Pet. 1:3-4) also said "Therefore, my brothers, be all the more eager to make your calling and election sure" (2 Pet. 1:10)
The same Paul, who said nothing "will be able to separate us from the love of God that is in Christ Jesus our Lord" (Rom. 8:39) also said, "I beat my body and make it my slave so that after I have preached to others, I myself will not be disqualified for the prize" (1 Cor. 9:27)