But ye shall receive power, after that the Holy Ghost [holy spirit] is come upon you: and ye shall be witnesses unto me [Jesus Christ] both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.
For we cannot but speak the things which we have seen and heard.
And when they had prayed, the place was shaken where they were assembled together; and they were all filled with the Holy Ghost [holy spirit], and they spake the word of God with boldness.
And the multitude of them that believed were of one heart and of one soul: neither said any of them that ought of the things which he possessed was his own; but they had all things common.
And with great power gave the apostles witness of the resurrection of the Lord Jesus: and great grace was upon them all.
And he [Jesus Christ] commanded us to preach unto the people, and to testify that it is he which was ordained of God to be the Judge of quick [living] and dead.
To him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins.
How then shall they call on him [God] in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?
And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things!
I Corinthians 1:17,18:
For Christ sent me [Paul] not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect.
For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.
II Corinthians 4:5:
For we preach not ourselves, but Christ Jesus the Lord; and ourselves your servants for Jesus’ sake.
II Corinthians 4:13:
We having the same spirit of faith, according as it is written, I believed, and therefore have I spoken; we also believe, and therefore speak.
II Corinthians 5:18-20:
And all things are of God, who hath reconciled us to himself by Jesus Christ, and hath given to us the ministry of reconciliation;
To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.
Now then we are ambassadors for Christ, as though God did beseech you by us: we pray you in Christ’s stead, be ye reconciled to God.
But speaking the truth in love, may grow up into him in all things, which is the head, even Christ.
For it is God which worketh in you both to will and to do of his good pleasure.
Do all things without murmurings and disputings:
That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world;
Holding forth the word of life; that I may rejoice in the day of Christ, that I have not run in vain, neither laboured in vain.
To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:
Whom we preach, warning every man, and teaching every man in all wisdom; that we may present every man perfect in Christ Jesus.
II Timothy 4:2:
Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine.
I Peter 3:15:
But sanctify the Lord God in your hearts: and be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear [reverence].