MacArthur says they are indispensable for salvation. Proper exegesis and personal experience do not support Lordship salvation. When used in the salvation passages, Lord especially emphasizes the deity of Christ. We ask that he trust a Person who lived 2,000 years ago, whom he can only know through the Bible, to forgive his sins. Salvation is free.
Lordship is very costly.
Faith is a gift bestowed by God upon unbelievers. Discipleship is a commanded work of obedience for believers. Both faith and discipleship are absolutely important, the one for salvation, and other for sanctification.