"…Repent and be baptized every one of you in the name of Jesus Christ for the remission of sins.."
We are told to repent (to think differently) and be baptized (immersed) in the name of Jesus Christ--not water or works. Salvation begins with recognizing that I am a sinner. In Isaiah 53:6 it describes sin as being turned to my own way. This sin of pride separates me from God. I need to turn to Jesus Christ and trust His shed blood on the cross, His burial and resurrection to bridge the gap between us--Trusting God to keep his promise: "For whosoever shall call on the name of the LORD shall be saved." ( Ro. 10:13) Trusting in anything or anyone--including myself--besides Jesus is a false salvation.
"…They that be whole need not a physician….I am not come to call the righteous, but sinners to repentance."
It seems that the more broken a person was, the more obvious it was that they needed Christ to help them. Self-righteousness gave a false sense of security to the Pharisees (Jewish religious leaders): however, the sinners knew their brokenness and came to Christ for His mercy. They did not have to "fix themselves up" to come--He accepted with grace those who came to Him by faith: "For by grace are ye saved through faith; and that not of yourselves: it is a gift of God: not of works, lest any man should boast. For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them." (Epe. 2:8-10) He even gives us the faith necessary to trust the promise! He washes the sins away with His mercy and He renews us. The "doing" is God's job--mine is to "...hear the word of the gospel and believe. (Acts 15:7) He redeems us (buys us) from iniquity and then purifies us unto good works.
Once again, the Good News is all about Christ! He creates the masterpiece of my life. How I wish that I would always hold my hands and heart open for His working! His working for His glory--Beautiful!