17 But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.
God is to be Thanked if and when one believes or obeys from the Heart, because if God would not have first given them a Heart to Fear Him according to the Covenant Jer 32:40
40 And I will make an everlasting covenant with them, that I will not turn away from them, to do them good; but I will put my fear in their hearts, that they shall not depart from me.
Without that, man cannot obey God from the Heart. The man by nature cannot obey God Rom 8:7
7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
The word mind phronéma is inclusive of the Heart as well it means:
thought, purpose, aspirations.
phrónēma (a neuter noun) – properly visceral opinion (the innermost, personal level of opinion); inner perspective as it determines (regulating) outward behavior, especially as it bears on the outward results (i.e. of exercising personal insight). Note the suffix, -ma, pointing to the result of the verbal idea. See 5429 (phronimos).
Thats why scripture speaks of blindness of Heart Eph 4:18
Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart:
And blindness of the Mind 2 Cor 3:14
But their minds were blinded: for until this day remaineth the same vail untaken away in the reading of the old testament; which vail is done away in Christ.
2 Cor 4:4
In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
The Mind is the intellectual aspect of the Heart, and so man by nature, his mind/heart is enmity against God, and not subject to obey God !
But thats exactly what one does when they become a believer, they obey God, they obey the Gospel which is antithesis to not obeying it as here told Rom 10:16
But they have not all obeyed the gospel. For Esaias saith, Lord, who hath believed our report?
Which is the exact opposite of those who Paul Thanked God for obeying the Gospel in Rom 6:17
But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.
The proud religious person will thank his freewill for any semblance of obedience to God !
The word obeyed in Rom 6:17 is the greek word hupakouó:
/hypakoúō ("obey") is acting under the authority of the one speaking, i.e. really listening to the one giving the charge (order). 5219 /hypakoúō ("to hearken, obey") suggests attentively listening, i.e. fully compliant (responsive).
to hearken to a command, i. e. to obey, be obedient unto, submit to,
And yet thats what the unregenerate heart/mind cannot do according to Rom 8:7 !
So once again, if we have Believed from the Heart, or Obeyed from the Heart the True Gospel, God is to be Thanked, that He delivered us over to its Power Rom 1:16 !