Just show me one verse that says 'believing' is an act of self righteous effort.
Faith in Christ, is to put Trust in Jesus as your Savior.
How?
"FAITH comes by HEARING" The Gospel.
The Gospel, is "the preaching of the Cross", and "The Cross is the power of God, unto Salvation".
So, when you give God your FAITH, because you have believed, after hearing "the preaching of the Cross", then God, gives you "the Gift of Salvation" and "The GIFT of Righteousness".
You then BECOME......"a new Creation"..........and now exist in the KOG< as a SON OF GOD, born again.
So, you dont need "FAITH" to get there later, as you are ALREADY THERE because God accepted your FAITH, ALREADY.