Oh, sorry. I should have gone after the "obligation" aspect... I knew that, my mistake
This is simple... God cannot lie (Tit.1:2; Heb.6:18) and has never sinned (2 Cor.5:21; 1 Pt.2:22; 1 Jn.3:5). Everything written in the Bible is true. Everything God has promised, whether of curses for disobedience or blessings for obedience, He is obligated to act upon every time. If He did not, then He would be showing favoritism, partiality, or respect to person, which He does not do (2 Sam.14:14; 2 Chr.19:7; Acts 10:34; Rom.2:11; Eph.6:9; Col.3:25; 1 Pt.1:17). If God did not enforce everyone of His words, then He would be a liar and unjust. God would be a transgressor, a sinner, and guilty (Jas.2:9-10).
Heb.5:9 -And being made perfect,
he became the author of eternal salvation unto all them that obey him;
2 Thess.1:8 -In flaming fire taking vengeance on them that know not God,
and that obey not the gospel of our Lord Jesus Christ:
If God says eternal salvation is for those who repent from sin, turning from their wicked ways, and follow Christ in obedience, then He is obligated to do so, lest He is a liar. But no lie is of the truth (1 Jn.2:21), and He is Truth (Jn.14:6). There is absolutely zero darkness in light (1 Jn.1:5). All liars are condemned (Rev.21:8, 27; 22:15). God is no liar (Tit.1:2; Heb.6:18) ;therefore, He is obligated to fulfill ALL HIS promises, whether for curses to the disobedient, or blessings to the obedient... simple right?