(Mat 3 KJV) In those days came John the Baptist, preaching in the wilderness of Judaea, {2} And saying, Repent ye: for the kingdom of heaven is at hand. {3} For this is he that was spoken of by the prophet Esaias, saying, The voice of one crying in the wilderness, Prepare ye the way of the Lord, make his paths straight. {4} And the same John had his raiment of camel's hair, and a leathern girdle about his loins; and his meat was locusts and wild honey. {5} Then went out to him Jerusalem, and all Judaea, and all the region round about Jordan, {6} And were baptized of him in Jordan, confessing their sins. {7} But when he saw many of the Pharisees and Sadducees come to his baptism, he said unto them, O generation of vipers, who hath warned you to flee from the wrath to come? {8} Bring forth therefore fruits meet for repentance: {9} And think not to say within yourselves, We have Abraham to our father: for I say unto you, that God is able of these stones to raise up children unto Abraham. {10} And now also the ax is laid unto the root of the trees: therefore every tree which bringeth not forth good fruit is hewn down, and cast into the fire. {11} I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire: {12} Whose fan is in his hand, and he will thoroughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire. {13} Then cometh Jesus from Galilee to Jordan unto John, to be baptized of him. {14} But John forbad him, saying, I have need to be baptized of thee, and comest thou to me? {15} And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered him. {16} And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him: {17} And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.

John the Baptist was a witness of what happened at the water:

It was at Jesus’ baptism that a great witness to Jesus’ ministry was given.

(Mat 27:27-54 KJV) Then the soldiers of the governor took Jesus into the common hall, and gathered unto him the whole band of soldiers. {28} And they stripped him, and put on him a scarlet robe. {29} And when they had platted a crown of thorns, they put it upon his head, and a reed in his right hand: and they bowed the knee before him, and mocked him, saying, Hail, King of the Jews! {30} And they spit upon him, and took the reed, and smote him on the head. {31} And after that they had mocked him, they took the robe off from him, and put his own raiment on him, and led him away to crucify him. {32} And as they came out, they found a man of Cyrene, Simon by name: him they compelled to bear his cross. {33} And when they were come unto a place called Golgotha, that is to say, a place of a skull, {34} They gave him vinegar to drink mingled with gall: and when he had tasted thereof, he would not drink. {35} And they crucified him, and parted his garments, casting lots: that it might be fulfilled which was spoken by the prophet, They parted my garments among them, and upon my vesture did they cast lots. {36} And sitting down they watched him there; {37} And set up over his head his accusation written, THIS IS JESUS THE KING OF THE JEWS. {38} Then were there two thieves crucified with him, one on the right hand, and another on the left. {39} And they that passed by reviled him, wagging their heads, {40} And saying, Thou that destroyest the temple, and buildest it in three days, save thyself. If thou be the Son of God, come down from the cross. {41} Likewise also the chief priests mocking him, with the scribes and elders, said, {42} He saved others; himself he cannot save. If he be the King of Israel, let him now come down from the cross, and we will believe him. {43} He trusted in God; let him deliver him now, if he will have him: for he said, I am the Son of God. {44} The thieves also, which were crucified with him, cast the same in his teeth. {45} Now from the sixth hour there was darkness over all the land unto the ninth hour. {46} And about the ninth hour Jesus cried with a loud voice, saying, Eli, Eli, lama sabachthani? that is to say, My God, my God, why hast thou forsaken me? {47} Some of them that stood there, when they heard that, said, This man calleth for Elias. {48} And straightway one of them ran, and took a sponge, and filled it with vinegar, and put it on a reed, and gave him to drink. {49} The rest said, Let be, let us see whether Elias will come to save him. {50} Jesus, when he had cried again with a loud voice, yielded up the ghost. {51} And, behold, the veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent; {52} And the graves were opened; and many bodies of the saints which slept arose, {53} And came out of the graves after his resurrection, and went into the holy city, and appeared unto many. {54} Now when the centurion, and they that were with him, watching Jesus, saw the earthquake, and those things that were done, they feared greatly, saying, Truly this was the Son of God.

Even though you might say that Jesus’ earthly ministry wasn’t finished until He rose from the dead, and then forty days later ascended into heaven, it was His death on the cross that was the goal of His ministry. He came to die. He came to spill His blood.

The Holy Spirit wants to work in our lives as well, giving us the power to tell others about our Savior.

I believe Jesus’ promise is as good to us as it was to the apostles:

Though it might not be a good idea to use this verse as a witness to the Trinity in Scripture, the truth of the Trinity is still seen in Scripture:

The concept of the Trinity is that there are three distinct persons, all having the attributes of deity, but yet there is only one God.