Here Allah tells us that He defends His servants who put their trust in Him and turn to Him in repentance; He protects them from the the worst of evil people and the plots of the sinners; He protects them, guards them and supports them, as He tells us elsewhere:
(Is not Allah sufficient for His servant) 39:36
(And whosoever puts his trust in Allah, then He will suffice him. Verily, Allah will accomplish his purpose. Indeed Allah has set a measure for all things) 65:3.
(Verily, Allah likes not any treacherous ingrate) means, He does not like any of His servants who bear these characteristics, i.e., treachery in covenants and promises whereby a person does not do what he says, and ingratitude is to deny the blessings, whereby one does not acknowledge or appreciate them.