Now the eleven disciples went to Galilee, to the mountain to which Jesus had directed them. And when they saw him they worshiped him, but some doubted. And Jesus came and said to them, “All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”
they saw Him - "they" may include the 500 of 1 Corinthians 15:6, as it is unlikely the apostles would be doubting at this point.
some doubted = can include the meaning of "hesitated," perhaps because they didn’t recognize Him in His glorified body until He began speaking.
go - in the original, this expresses an assumption — "as you are going"
name - singular — the Father, Son and Holy Spirit have one name
"Here is evidence for the trinity of God: one God (the name) who subsists in three Persons (Father, Son, and Holy Spirit). Each of the three is distinguished from the others; each possess all the divine attributes; yet the three are one. This is a mystery that no analogy can illustrate satisfactorily. The sun, sunlight, and the power of the sun may come close to a suitable illustration." (Ryrie)
"These were the 'poor of the flock' (Zechariah 11) to whom in distant Galilee and far from Jerusalem the Great Shepherd connected Himself, and whom He commissioned to proclaim His rights as King and the laws of His Kingdom throughout the whole earth. He assured them of the donation of all power given to Him both in heaven and in earth, and promised to be with them until the consummation of the age. That consummation would have then come if Israel had repented; but the two tribes in Jerusalem sent Stephen (Acts 7) to say 'We will not have this Man to reign over us,' and the ten tribes in Rome, the capital of the Dispersion, committed a similar message to Paul (Acts 28). Hence this commission is now in abeyance, but will be resumed, and obeyed, when Divine relations are once more resumed with Israel. There is no Ascension in this Gospel, for all in it relates to the King and to the Kingdom which He proposed to set up upon the earth; and so He promises to be with them until the predicted hour came of the establishment of the kingdom. The interpretation of this commission belongs, therefore, to the Hebrew church, represented by the apostles and the five hundred brethren. The Church of God — the 'secret' revealed in Ephesians — does not here appear, for its home in heavenly, and its commission is to take out from both Hebrews and Gentiles an election to heavenly glory." (Williams)
That this "commission" cannot be intended for the body of Christ, the Church of the age of grace, can be seen by its contrast with 1 Corinthians 1:17, where Paul writes: For Christ did not send me to baptize but to preach the gospel, and not with words of eloquent wisdom, lest the cross of Christ be emptied of its power.