A lot of folks make a lot of promises. Promises that they can't keep. Promises, that if they were kept, would still be insufficient to meet our needs.
This is the promise that the Father has promised us - eternal life. If we abide in Him and His Son, we will keep this promise. Eternal life with them is exactly what we need.
1 John 2:24-29; NKJV
24 Therefore let that abide in you which you heard from the beginning. If what you heard from the beginning abides in you, you also will abide in the Son and in the Father.
25 And this is the promise that He has promised us — eternal life.
26 These things I have written to you concerning those who try to deceive you.
27 But the anointing which you have received from Him abides in you, and you do not need that anyone teach you; but as the same anointing teaches you concerning all things, and is true, and is not a lie, and just as it has taught you, you will abide in Him.
28 And now, little children, abide in Him, that when He appears, we may have confidence and not be ashamed before Him at His coming.
29 If you know that He is righteous, you know that everyone who practices righteousness is born of Him.
