1 Kings 8:56 KJV
Blessed be the Lord, that hath given rest unto his people Israel, according to all that he promised: there hath not failed one word of all his good promise, which he promised by the hand of Moses his servant.
When God promises something there is no limit to his promise. His integrity is stellar. He is the same yesterday, today and forever (Heb. 13:8). For the child of God his promises are the staple of our lives. He never promises something that is not his will and every time we benefit from them we are changed. Things become established in our lives when the promise is manifested.
The promises of God reveal the nature of God. For instance, when we experience Rom. 10:9-10 and know our life has been changed because we are now saved, we realize this promise is for all people. Since our only part was to believe and say so we know it was not something unique that God did just for us. Everyone has the capability to believe. This shows us that salvation is universal and that God doesn't want anyone to miss out. His love is universal. It is not dependent on where we live or our language group.
While there are promises in the Bible that have specific conditions added the conditions are not designed for exclusion. For instance Jer. 29:13 tells us: You will seek me and find me when you search for me with all your heart. Without the seeking the finding will not happen and with the seeking the finding is certain.
Conditions are designed to show us the way into obtaining the promise. They are like a GPS so we know when we have reached out destination. When that happens we have assurance of receiving what is promised by God himself. It is not the result of emotions, although you may have good feelings. It is not the result of reasoning as doubts may come to dissuade you. It is similar to having a ticket for a performance. Once you have the ticket you know you are going to be admitted. The promise is the ticket. Just apply the conditions and it's yours. There is no reason to strive; simply trust, obey and enter God's rest