"Does saving faith require a trust in the righteousness of Christ alone as the grounds of our justification? Or may a person have a different view of the gospel and still be a Christian?"
Here is a Quote by Pastor Charles Haddon Spurgeon (1834 - 1892)
"And now the plan of salvation is simply declared unto you—'Whosoever believeth in the Lord Jesus Christ shall be saved.' For you who have violated all the precepts of God, and have disdained his mercy and dared his vengeance, there is yet mercy proclaimed, for 'whosoever calleth upon the name of the Lord shall be saved.' 'For this is a faithful saying and worthy of all acceptation, that Christ Jesus came into the world to save sinners, of whom I am chief;' 'whosoever cometh unto him he will in no wise cast out, for he is able also to save unto the uttermost them that come unto God by him, seeing he ever liveth to make intercession for us.' Now all that God asks of you—and this he gives you—is that you will simply look at his bleeding dying son, and trust your souls in the hands of him whose name alone can save from death and hell." - From Spurgeon's sermon Compel Them To Come In