True Christians have been saved from the penalty of sin for one reason alone: because of “the love of God, which is [manifested] in Christ Jesus our Lord.”
St. John wrote by divine inspiration:
Let us understand this clearly and remember it always. It is not our love to Him, but His love to us, that saves us — and it is His love to us that keeps us saved. This is where we must begin the Christian life.
A wayward husband returned to his grieving wife one day, after many months of living in sin. Sobbing his heart out in remorse and shame, he told her how often he had longed to be home again with the wife he knew to be so true to him. Asked why, then, he had not returned sooner, he explained that he was ashamed; to which his wife replied: “John, I want you to know something and never forget it: I love you.” John sobbed in response: “Who wouldn’t want to live for a woman like this!”
Just so it is the knowledge that Christ loves us no matter what; that nothing shall ever separate us from His love; it is this that makes the sincere believer determine, by God’s grace, to be always true to Him.
Thus the Scripture doctrine of the believer’s eternal security in Christ by no means leads to careless living. On the contrary, it affords the greatest possible motivation to “live soberly, righteously and godly in this present world” (Tit. 2:11,12).