Then you're still on the wrong side of the cross,
The wrong side of the cross? How can you say something like that and not cringe?
because those who believe are no longer under a any schoolmaster.
Those who believe are not under the OLD school master, the law.
The law was a teaching tool, a shadow of Christ.
When Christ in the light came, his shadow was gone, for there are no shadows in light.
Believers have no need for a schoolmaster, as Paul tells us in Galatians. We have the indwelling Spirit.
The Holy Spirit is the Teacher.
John 14:26 But the Advocate, the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you.
John 16:13
However, when the Spirit of truth comes, He will guide you into all truth. For He will not speak on His own, but He will speak what He hears, and He will declare to you what is to come.
Jesus taught the law while he walked this earth, and that's why you're confused, and think you have to obey. Then he went to the cross and accomplished what the law could not do.
You don't seem to believe our Lord accomplished the only obedience that would not fall short of the glory of God, and was adequate for every sin every person in the world would ever commit. He said "It is finished", but you think you have to keep performing (even though we all can see you fail at every turn).
Train ourselves. Work out our salvation.
Luke 6:40
A student is not above his teacher, but everyone who is
fully trained will be like his teacher.
1 Corinthians 9:25 Everyone who competes in the games goes into
strict training. They do it to get a crown that will not last; but we do it to get a crown that will last forever.
1 Timothy 4:7, 8 Have nothing to do with godless myths and old wives’ tales; rather,
train yourself to be godly. For physical training is of some value,
but godliness has value for all things, holding promise for both the present life and the life to come.
2 Timothy 3:16 All Scripture is God-breathed and is useful for teaching, rebuking, correcting and
training in righteousness,
Titus 2:4 Then they can
train the younger women to love their husbands and children,
Hebrews 5:14 But solid food is for the mature, who by constant use have
trained themselves to distinguish good from evil.
Hebrews 12:11 No discipline seems pleasant at the time, but painful. Later on, however, it produces a harvest of righteousness and peace for those who have been
trained by it.