Romans 5:2:

By whom also we have access by faith into this grace wherein we stand, and rejoice in hope of the glory of God.

See also:

Grace + Faith = Miracles
You Have Faith
Who You Are and What You Have
Healing and Effort
Balance: Avoiding Ditches on Either Side of the Road
Objection: We Are Healed by Jesus’ Stripes, Not by Jesus’ Stripes PLUS Our Faith
Objection: God Sometimes Withholds Healing to Test Your Faith
Objection: Mark 16:18 Does Not Say, “They Shall Recover IF They Have Enough Faith,” Yet Faith Healers Blame the Sick for Not Believing
Objection: If Healing Were Really Based 100% on Grace, Everyone Would Be Healed