Deuteronomy 11:26 Behold, I set before you this day a blessing and a curse; 27 A blessing, if ye obey the commandments of the Lord your God, which I command you this day. 28 And a curse, if ye will not obey the commandments of the Lord your God.
God never blesses deliberate disobedience. There are times, when a person is in genuine ignorance God may wink, but the Bible clearly states that if I regard iniquity in my heart, The Lord will not hear me. Which means that if one knows something is wrong, and chooses to continue doing so, then it becomes vanity to quote promises confidently.
Fear has torment and uncertainty, while faith has solid foundations of factual evidences, manifested in a person’s experiences with God, and upon which one’s decisions are made with confidence. Thus, the positive assurance David is manifesting is based upon two things: [1] He obeys God’s voice, and [2] He has many literal experiences with God which he can point to as undeniable evidence of God’s presence with him.
It’s worthy of note that if anyone else had dared to make such an offer, such a decision could be placed in the “presumption” column, if they did not have substance and evidence to back up such an offer. If a person claims the promises of God with apparent confidence, he/she had better have substance and evidence to make such claims, or their consequent actions can be presumption.
Hebrews 11:1 Now faith is the substance of things hoped for, the evidence of things not seen.
May The Lord add His blessing to the study of His word. God bless!