We are not saved on the basis of Christ plus something—such as our good life, church attendance, keeping the commandments, or taking the sacraments. We are saved on the basis of Christ period. We must be satisfied with the thing that satisfies God. The only thing that satisfied God’s anger against our sin was His Son’s death on the cross. That’s why in John 19:30 as Christ hung on the cross, He proclaimed, “It is finished!” That word “finished” means “paid in full”.
If we are trusting Christ plus anything we have done, then we are not agreeing with God that His Son’s death is sufficient to pay for our sins. Our trust must be in Christ alone as our only way of salvation.
Furthermore, the Bible makes it clear that eternal life is a free gift. Ephesians 2:8-9 tells us, “For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.” If a person is depending on anything in addition to Christ to get them to heaven, then they are not accepting salvation as a free gift.