God calls all people everywhere to repent (Acts 17:30). Peter wrote in 2 Peter 3:9, “The Lord is not slack concerning His promise, as some count slackness, but is longsuffering toward us, not willing that any should perish but that all should come to repentance.” Furthermore, Jesus declared in Luke 24:46–47, “Thus it is written, and thus it was necessary for the Christ to suffer and to rise from the dead the third day, that repentance and remission of sins should be preached in His name to all nations, beginning at Jerusalem.’” This is the Gospel to the Nations that is described, “Then God has also granted to the Nations repentance to life” (Acts 11:18). Jesus expressed, “I have not come to call the righteous, but sinners, to repentance” (Luke 5:32). Were you called to repent?
Many have a misconception of what repentance is. Sorrow is not repentance (2 Cor 7:9–10). Changing behavior without changing the mind is not repentance. Changing the mind without changing behavior is not repentance. The Gospel declared throughout the nations is that, “they should repent and convert to God doing works compatible with repentance” (Acts 26:20; cf. Heb 6:1). In Greek, repent is made of two words “change” and “mind,” so that the mind must change to change one’s behavior. Repentance is modifying our understanding, reforming our intellect, and altering our thinking, so that our behavior changes when our hearts are compelled by Christ’s love (2 Cor 5:14–15). A true believer will show works of repentance (Mark 1:15; John 3:20–21; Acts 8:22). When someone truly believes, that person will repent, and when a believer truly repents, that believer will obey the Gospel putting to death the old self, being buried with Christ in baptism, to be raised by grace into the newness of life (Rom 6:1–7; Eph 2:4–7; Col 2:12–13; cf. 1 Cor 15:1–4).
Jesus said, “Remember therefore from where you have fallen; repent and do the first works, or else I will come to you quickly and remove your lampstand from its place — unless you repent,” (Rev 2:5). Jesus also said in Luke 13:3, 5, “Repent or likewise be ruined.” Otherwise, repent and cause rejoicing in Heaven. Jesus revealed, “I say to you that likewise there will be more joy in heaven over one sinner who repents than over ninety-nine just persons who need no repentance. […] Likewise, I say to you, there is joy in the presence of the angels of God over one sinner who repents” (Luke 15:7, 10). “Repent therefore and be converted, that your sins may be blotted out, so that times of refreshing may come from the presence of the Lord,” (Acts 3:19). “Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins;” (Acts 2:38).
By considering the words of Jesus and His Apostles, is repentance necessary for salvation? The answer is clear.
The Breath of God 
Amen! The only message that you hear today is “salvation by grace through faith”, but the Gospel message spoken by John the Baptist, Christ and the Apostles was, “Repent, for the Kingdom of God is at hand.” Mt 3:2, 4:17, Acts 2:38 Many of the churches and believers of America have reached a very sad state where they profess that they know God; but in works they deny him, (Titus 1:16) coming even to equate obedience with legalism. May God have mercy on us and help us to preach Salvation the way the New Testament teaches.
Preach it brother!