"There is a wide difference between your religion and my faith," said a Christian lady to one in whose spiritual condition had long concerned her.
"Indeed," said he, "how is that?"
"Your religion," she replied, "has only two letters in it, my faith has four."
"What do you mean," said he, "by two letters and four?""Why, your religion says you are to d-o; DO; whereas my faith says it is d-o-n-e; DONE."
When the Lord Jesus Christ died on the cross He cried out, "It is finished" (Jn. 19:30). The work of our salvation was FINISHED, DONE, ACCOMPLISHED and COMPLETED. We simply need to trust and rest in what THE Savior has accomplished. Notice I emphasized "THE"; that is because Jesus is "THE" only way man can spend eternity with God (Jn. 14:6)!
Salvation is not working; it is RESTING on the WORK of Another, even the Lord Jesus Christ. "But to him that worketh not, but believeth on Him that justifieth the ungodly, his faith is counted for righteousness" (Rom. 4:5).
Religion is man trying to bring himself to God by human effort, by good works, by ritualism, by traditionalism, by sacraments, etc. Salvation is Christ bringing us to God on the basis of what He did for us on the cross: "For Christ also hath once suffered for sins, the just for the unjust, that He might bring us to God" (1 Peter 3:18).
This concept is perfectly described in Acts 13:43 which says, "Now when the congregation was broken up, many of the Jews and religious proselytes followed Paul and Barnabas: who, speaking to them, persuaded them to continue in the grace of God." Grace, as it is used in the New Testament, comes from the Greek χάρις (charis), meaning "unmerited favor, or that which is received as a gift." Therefore, I understand this verse to be saying that the religious Jews, and the religious Gentile converts to Judaism, left their religion and placed their faith in the finished work of Christ on their behalf!
Working results in my exhausting; trusting results in my praise to Him!