God will not break the smallest part of His covenant promises. Every word that came out of His lips He will cause to happen. Every elect shall be saved fully. Put all your trust then in Him, no matter what happens here on this earth. Not only will He keep His word, but He is every minute keeping His promises.
Heavenly glory is ahead.
Although we may have graduated from high school, college, or university, we, from a spiritual point of view, are still in need of much education. He does not write this to little children. He is not exhorting a few people here and there. Plainly then he includes himself. We all need to number our days and set our hearts on wisdom.