Heresy is not a term that I use very often, but Lordship salvation is so contrary to the Reformation doctrine of grace alone through faith alone that I cannot help but condemn it. Lordship salvation teaches that one cannot receive Jesus as Savior without submitting to Him as Lord.
In Titus 2:11-14, our salvation is described as being trained by grace to do what is godly, righteous, and good, and to renounce doing what is ungodly, so God graciously teaching us to obey His laws for how to do those things is itself part of the content of His give of salvation. Submitting to these laws through faith is what it means to submit to Jesus as Lord and is by no means contrary to grace alone through faith alone. Luther said that we are justified by faith alone, which is true insofar as there are no works that we can do to earn our salvation, however, he also taught along the lines that faith is never alone, which is true insofar as the same faith by which we are justified is also expressed as obedience to God's law, which is essentially what Paul was saying in Romans 3:28-31, where we are justified by faith apart form works, but our faith does not abolish our need to obey God's law, but rather the same faith by which we are justified also upholds God's laws by leading us to obey it. Luther said:
"Faith must of course be sincere. It must be a faith that performs good works through love. If faith lacks love it is not true faith. Thus the Apostle bars the way of hypocrites to the kingdom of Christ on all sides. He declares on the one hand, "In Christ Jesus circumcision availeth nothing," i.e., works avail nothing, but faith alone, and that without any merit whatever, avails before God. On the other hand, the Apostle declares that without fruits faith serves no purpose. To think, "If faith justifies without works, let us work nothing," is to despise the grace of God.
Idle faith is not justifying faith. In this terse manner Paul presents the whole life of a Christian. Inwardly it consists in faith towards God, outwardly in love towards our fellow-men."
"The argument is sophistical and the refutation is resolved grammatically. In the major premise, "faith" ought to be placed with the word "justifies" and the portion of the sentence "without works justifies" is placed in a predicate periphrase and must refer to the word "justifies," not to "faith." In the minor premise, "without works" is truly in the subject periphrase and refers to faith.
We say that justification is effective without works, not that faith is without works. For that faith which lacks fruit is not an efficacious but a reigned faith. "Without works" is ambiguous, then. For that reason this argument settles nothing.
It is one thing that faith justifies without works; it is another thing that faith exists without works."
This is a destructive heresy, because it confuses justification with sanctification. By faith alone, our sins are forgiven, due to the price Jesus already paid on the cross. Once saved, we are called to a life of good works, in gratitude for our salvation, rather than in fear of not earning it.
Titus 2:11-14 notably does not say that we need to do those things in order to earn our salvation or that we will do those things after we have been saved, but rather it describes the content of our salvation as being trained by grace to do those things, so it is not confusing justification with sanctification. Our salvation is from sin (Matthew 1:21) and sin is the transgression of God's law (1 John 3:4), so being trained by grace to live in obedience to God's law through faith is what it means to receive the content of gift of Jesus saving us from living in transgression of God's law, and one can't receive salvation while rejecting the content of salvation.
Lordship salvation teachers are like modern-day Pharisees:
While some Pharisees were not with their problems of pride, hypocrisy, and a lack of compassions, but their devotion to obeying God's word is something that should be admired rather than sneered at. Paul never stopped identify as a Pharisee (Acts 23:6), so most of the books of the NT are written by a Pharisee, and in 1 Corinthians 11:1, he instructed us to follow his example, so we are instructed to follow the example of a Pharisee.
I am not saying that believers in Lordship salvation are unsaved, because only Jesus can judge their hearts. Their teaching, however, is destructive, because it turns people away who would otherwise be saved. When Jesus forgave the thief on the cross, his belief was enough.
On the contrary, it is leading people away from the content of our salvation that is turning people away who would otherwise be saved. Someone can still have faith while being physically prevented from expressing it, but if your arms and feet aren't nailed to a cross, then you don't have that excuse.
This is Jesus' warning for Lordship salvation teachers today:
Please note that they call Jesus "Lord," and attempt to justify themselves by their works, and Jesus' answer is "I never knew you. Depart from me."
What is the work of God that profits unto salvation?
The Father has made His will known through His law (Psalms 40:8), and in Matthew 7:21-23, Jesus said that only those who do the will of the Father will enter the Kingdom of heaven and that he would tell those who are workers of lawlessness to depart from him because he never knew them, so his warning was for those who do not teach Lordship salvation.
Jesus answered, "The work of God is this: to believe in the one he has sent."
In John 3:36, it equates believing in Jesus with obeying His commands, so we can't believe in him without submitting to him as Lord.
Let us always remember that God considers us righteous by faith alone. No amount of obedience or disobedience to the Law can affect this irreversible and eternal position (
John 5:24; Rom 4:5; Gal 2:16). Neither should our behavior affect our assurance in Christ, “in whom we have boldness and confident access through faith in Him” (Eph 3:12). If you keep these truths in mind, you can obey from a heart of gratitude instead of from compulsion and fear. Salvation is liberating (
John 8:32, 36)!
https://faithalone.org/grace-in-focus-articles/the-harsh-hand-of-lordship-theology/
We express our character traits through our actions, when when God declares us to be righteous by grace through faith, He is also declaring us to be someone who expresses his righteousness through our actions in obedience to His instructions for how to do that found in His law. In Psalms 119:142, God's law is truth, and in John 8:31-36, it is sin in transgression of God's law that puts us in bondage while it is the truth that sets us free.
The free grace of the Gospel goes against human reasoning. How could faith, apart from works, save us? It seems too simple, too good to be true. Paul had something to say about this:
In Psalms 119:29, David wanted God to be gracious to him by teaching him to obey His law, so that is again the content of the free grace of the Gospel.
John 3:14-15
And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: That whosoever believeth in Him should not perish, but have eternal life.
In Matthew 19:17, Jesus said that obedience to God's commands is the way to enter eternal life, so again obedience to God's commands is what it means to believe in Him. When we express God's nature through our obedience to His law, was are testifying about what we believe about who God is, or in other words we are believing in Him.