'Testimony' in the Bible

And with great ability and power the apostles were continuously testifying to the resurrection of the Lord Jesus, and great grace [God’s remarkable lovingkindness and favor and goodwill] rested richly upon them all.

So, when Peter and John had given their testimony and preached the word of the Lord, they started back to Jerusalem, preaching the good news [about salvation] in many Samaritan villages [along the way].

He commanded us to preach to the people [both Jew and Gentile], and to solemnly testify that He is the One who has been appointed and ordained by God as Judge of the living and the dead.

So Paul and Barnabas stayed for a long time, speaking boldly and confidently for the Lord, who continued to testify to the word of His grace, granting that signs and wonders (attesting miracles) be done by them.

solemnly [and wholeheartedly] testifying to both Jews and Greeks, urging them to turn in repentance to God and [to have] faith in our Lord Jesus Christ [for salvation].

and I saw Him saying to me, ‘Hurry and get out of Jerusalem quickly, because they will not accept your testimony about Me.’