If we keep God’s commandments, He will prolong our days  -  Deuteronomy 4:40

Thou shalt keep therefore his statutes, and his commandments, which I command thee this day, that it may go well with thee, and with thy children after thee, and that thou mayest prolong thy days upon the earth, which the LORD thy God giveth thee, for ever.

This promise was specifically given to Israel but the principle of it can be applied to all believers. If we are obedient to God’s Word, we will experience all the blessings that God has for us.