Gurus come from Sach Khand under the Order of the Lord for taking back the Souls

They are free from the bondage of Body and Mind

Our soul is a particle of God, but it has been imprisoned in the cage of the body and mind. Saints come from the original home, which is the true home of all the souls, so that they may take souls back and unite them with the Lord. The Lord Himself, according to whose orders the souls come into the world, comes in the form of the Master and says, "Come to your abode of peace by transcending the three gunas."

He, who sent you here, now calls you back. Come home to this land of calm, which no winds of passions can ruffle.

Dhanasri M5, 678-2

The Masters are one with the Lord. They come here simply to redeem the souls. In the hymns of all the holy men it is said that the Masters come to the world with the mission of redeeming the souls. 

Shamas-i-Tabrez says:

You do not know what kind of birds we are, or what we are reciting silently. We are apparently beggars in this world; find the Reality and you will see that we are kings. We appear to be poor, but if you look into our hearts you will find what treasures we have. Since we are kings in our own land. What does it matter if we are in prison here for a while? How can we live forever in this house? All of us are guests in this house. We have made promises to ouar king; nd we shall not go back on our promises. As long as we are wearing this mantle (of human body), we do not grieve, nor cause grief to anyone. We are full of Light and blessing as in Heaven we eat, make merry and laugh.

Guru Gobind Singh similarly says, "From duality we merged into One. I had no desire to come into this world, but the Lord so willed it and sent me here."

From two we became one. I did not like to come; the Lord willed it, and sent me to this world.

Bachiter Natak, Adlyai 5

Kabir Sahib also says:

Oh Kabir, we are the knowers of the secret. We have come here as ordered.