Deuteronomy 30:2
And shalt return unto the Lord thy God, and shalt obey his voice according to all that I command thee this day, thou and thy children, with all thine heart, and with all thy soul; (Deuteronomy 30:2)
Return.
 There must also be a turning away from sin and a return to the worship of Jehovah (see Neh. 1:8, 9). Sincerity would be reflected in obedience.