The object of our Faith is God's Love which was manifested in Christ Jesus.
If a person is struggling with Unbelief you must convince them of God's Love.
Perfect Love casts out Fear (1Jn 4:18) which is simply a manifestation of Unbelief (Mar 4:40.)
When we are overwhelmed with an awareness of God's Love we experience Joy in Him and so we are able to Receive whatsoever we desire (Mar 11:24.)
These things have I spoken unto you, that my joy might remain in you, and that your joy might be full. - Joh 15:11
Christ Jesus experienced perfect Joy because He heard His Father say "This is my BELOVED son in whom I am well pleased" - Mat 3:17. He knew He was loved!
Faith comes by hearing the Word of God (Rom 10:17.) The Word of God tells us that God so loved the world that He gave Himself for us individually (Joh 3:16.)
"In Jesus' name" means in the revelation of God's Love !
Let the Abundant Life of Christ Jesus manifest in you as you are filled with the Knowledge of Christ Jesus (Joh 10:10) or, as Paul said it:
And to know the love of Christ, which passes knowledge, that you might be filled with all the fulness of God. - Eph 3:19