Jesus promised that he would not leave us alone but would send the Counselor, who would come alongside to help. This Counselor, known as the Holy Spirit, is free to work in us as we empty ourselves of known sin and seek to be continuously filled with his indwelling power. (Discipleship Essentials p. 121)
"If you love me, you will keep my commandments. And I will ask the Father, and he will give you another Helper, to be with you forever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you. "I will not leave you as orphans; I will come to you… But the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you.
John 14:15-18, 26
Additional Scripture: John 16:5-15