New International Version
I have declared to both Jews and Greeks that they must turn to God in repentance and have faith in our Lord Jesus.

American Standard Version
testifying both to Jews and to Greeks repentance toward God, and faith toward our Lord Jesus Christ.

Berean Study Bible
testifying to Jews and Greeks alike about repentance to God and faith in our Lord Jesus Christ.

Douay-Rheims Bible
Testifying both to Jews and Gentiles penance towards God, and faith in our Lord Jesus Christ.

English Revised Version
testifying both to Jews and to Greeks repentance toward God, and faith toward our Lord Jesus Christ.

King James Bible
Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ.

World English Bible
testifying both to Jews and to Greeks repentance toward God, and faith toward our Lord Jesus.

Young's Literal Translation
testifying fully both to Jews and Greeks, toward God reformation, and faith toward our Lord Jesus Christ.

Acts 20:21 Additional Translations ...