Some people believe that Jesus Christ is necessary for salvation but also believe they must be baptized and live a good life to merit eternal life. In other words, they trust in Christ plus works.
We must ask: “What satisfies God in terms of our salvation?” In this, two things are clear from Scripture.
First, when Christ died on the cross He did not make a down payment for our sins. He made the full payment. When He died on the cross, He exclaimed, “It is finished” (John 19:30)!
Finished certainly indicates “paid in full.” Christ did everything that was necessary for us to be forgiven and eternally His.
Second, God accepted Christ’s sacrifice as complete: “[Jesus] Himself is the propitiation for our sins, and not for ours only but also for the whole world” (1 John 2:2). Propitiation means “satisfaction.” Jesus Christ then is the satisfaction for our sins. God accepted His Son’s death as a total and complete payment for sins. Jesus Christ is therefore not part of a formula. He is the formula!
That’s why we must come to Him as sinners, recognize He died for us and rose again, and trust in Christ alone as our only basis for salvation. If God is satisfied with Christ’s sacrifice alone for our salvation, then we must be satisfied with Christ’s sacrifice alone for our salvation.
If one is trusting Christ but only as a necessary addition to works, he is not a recipient of eternal life. He is not satisfied with what satisfies God. God is asking us to agree with Him about His Son’s complete payment for our sins. If we are trusting Christ in addition to something, then we are not accepting the fact that His Son paid for sin in its entirety. We are seeking to add to what He has done by trusting in our baptism, our church attendance, our good life, etc. Because it is deficient in our equation, we are basically saying that Christ’s death was disappointing.
The Bible speaks of eternal life being a free gift by grace—favor we do not deserve. Scripture also assures us that we can know for certain we are saved: “These things I’ve written to you who believe in the name of the Son of God, that you may know that you have eternal life” (1 John 5:13).
If salvation were based on Christ plus something we have done, we could never be completely sure we are going to heaven. But praise God that eternal life is based on Christ alone!