John 14:10-12

John 14:10-12. Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works. Believe me that I am in the Father and the Father in me: or else believe me for the very work’s sake. Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and greater works than these shall he do; because I go unto my Father.

The Lord Jesus Christ, after he had gone back to heaven gave to his servants the power to do these "greater works" - the Holy spirit resting upon them, - in the gathering in of the nations unto their Lord. Whereas Christ kept to one little country, he sent his first disciples, and he sends us still to preach the gospel to every creature in the whole world, and he clothes his servants with all needful authority and power to do the work he has committed to their charge.