What were the main teachings of the Bhakti saints?

The following were the main teachings of the Bhakti saints:

1. There is only one God and He alone ought to be worshipped.
2. God can be reached through love and absolute devotion to him. A Bhakta or a devotee should surrender himself completely to the will of God.
3. A Bhakta should not have any attachment to worldly things and there should be complete unity between man and God.
4. The people should have complete faith in their guru who teaches them total devotion to God.