It is true, there is not an immediate acting of faith upon the Father, but by the Son. “He is the way, the truth, and the life: no man cometh unto the Father but by him,” John 14:6. He is the merciful high priest over the house of God, by whom we have access to the throne of grace: by him is our manuduction unto the Father; by him we believe in God, 1 Pet. 1:21. But this is that I say,—When by and through Christ we have an access unto the Father, we then behold his glory also, and see his love that he peculiarly bears unto us, and act faith thereon. We are then, I say, to eye it, to believe it, to receive it, as in him; the issues and fruits thereof being made out unto us through Christ alone.
Though there be no light for us but in the beams, yet we may by beams see the sun, which is the fountain of it. Though all our refreshment actually lie in the streams, yet by them we are led up unto the fountain. Jesus Christ, in respect of the love of the Father, is but the beam, the stream; wherein though actually all our light, our refreshment lies, yet by him we are led to the fountain, the sun of eternal love itself. Would believers exercise themselves herein, they would find it a matter of no small spiritual improvement in their walking with God.
– John Owen –
from Of Communion With God, volume 2 of Works, pages 22-23