Oh, that you would come and begin simply to listen to His Word and to ask only the one question: Does He really mean that I should abide in Him? The answer His Word gives is so simple and so sure: By His almighty grace you now are in Him; that same almighty grace will indeed enable you to abide in Him. By faith you became partakers of the initial grace; by that same faith you can enjoy the continuous grace of abiding in Him. Andrew Murray
Abide in Me, and I in you. As the branch cannot bear fruit of itself unless it abides in the vine, so neither can you unless you abide in Me. (John 16:4)
Abiding in Christ requires a continuous efforts and improvement.