A covenant is an agreement between two parties to exchange resources so that they cover for each another.
Where one is weak, he calls on his or her covenant partner to supply strength in that situation so that he can walk in the strength of his partner and appear to the outsider as being that powerful.
This is what God meant when He said my Grace is sufficient for you, in your weakness shall my strength be made perfect. God was speaking as our covenant partner saying, where you are weak is where the opportunity lies for my power and strength to be made manifest in you.
This is why Paul exclaimed, “I will rather glory in my infirmities that your power may rest upon me.” This is the covenant we have with our God and that’s why we are guaranteed to win in life.
This covenant of supply goes both ways. The one you call upon to help you with his grace in a time of need also has his “needs” he has made known to you to which he asks you to step up to.