So according to your logic, these Jews in Acts 2:37 already believed the gospel, which means they were already saved (according to Romans 1:16) yet this was before they repented and received water baptism, which is not in harmony with your argument, so something has to give. Simply believing "mental assent" that Jesus was the Messiah and they were guilty of crucifying Him does not constitute believing the gospel. According to the apostle Paul, the
gospel is the power of God unto salvation to everyone that
BELIEVES.. (Romans 1:16) but
according to "your gospel," those who believe the gospel remain lost until later, after they repent and receive water baptism, which is not in harmony with Acts 10:43-47; 11:17,18; 15:8,9; 13:39; 16:31; 26:18; Romans 1:16 or 1 Corinthians 15:1-4. *You are not properly harmonizing all of Scripture with Scripture in order to reach the proper conclusion on doctrine. You are simply isolating your pet verses, building doctrine on them and ignoring the rest of Scripture that does not harmonize with your biased doctrine.
Jamison, Fausset, and Brown Commentary makes not of the importance of the Greek in Ananias' statement. When Ananias tells Paul to "arise, be baptized, wash away your sins, calling on the name of the Lord," the tense of the last command is literally "having called" (aorist middle participle). "Calling on [epikalesamenos] --- 'having (that is, after having) called on,' referring the confession of Christ which preceded baptism." [Jamison, Fausset, and Brown Commentary, vol. 3 pg. 160]. Kenneth Wuest picks up on this Greek nuance and translates the verse as follows: "And now, why are you delaying? Having arisen, be baptized and wash away your sins, having previously called upon His Name." (Acts 22:16, Wuest's Expanded NT).
In Acts 22:16, how did baptism "wash away" Paul's sins? Well, it couldn't do this literally, for Christ literally "put away sin by the sacrifice of Himself" (Hebrews 9:26). The language in Acts 22:16 is similar to the statement of Christ when He took the bread and said, "This is my body" (Matthew 26:26). The bread was only the emblem of His body. Baptism is the emblem of the washing away of sins by the death of Christ. Every time a believer is immersed he washes away his sins in the same sense Paul did: not literally, but ceremonially, pointing to the death of Christ by which sins were actually washed away. Greek Scholar A.T. Robertson explains: As in Romans 6:4-6 where baptism is the picture of death, burial and resurrection, so here baptism pictures the change that had already taken place when Paul surrendered to Jesus on the way. Baptism here pictures the washing away of sins by the blood of Christ. Therefore to take Paul's statement in Acts 22:16 as anything more than a metaphor is to confuse the symbolic rite with what the rite represents.
Acts 2:21 And everyone who "calls on the name of the Lord" will be saved.
Romans 10:13 for, Everyone who "calls on the name of the Lord" will be saved.
In calling on the name of the Lord to be saved, we are relying on the name of the Lord, trusting in Him for salvation. When you call upon Jesus to save you to it is that you trust in Him to come to your aid. Inherent in your calling upon Jesus is the essential faith that He can and will save you. So, in essence, to call on the name of the Lord unto salvation is to trust exclusively in Jesus as the ALL-sufficient means of your salvation, that He alone will save you.