A birthright is a gift from God, and like all the gifts and blessings God has for us we sometimes have to wait for them. The problem with most people is, we want what we want when we want it. Often times we take matters into our own hands, not waiting on the promises of God and we do things that we regret later on in life. When we start to think and function in the Spirit of God then and only then will we learn to receive, accept and appreciate the gifts that are for us from God. This is the Esau in all of us.
The Jacob in us also want what we want when we want it. We are covetous by nature, wanting what the other person has. When then take advantage of and manipulate them in such away that they would give us just what we wanted of theirs. BUT, when the Jacob in us starts to operate in the spirit of God, we too would wait on the Lord to bless us with the blessing He has just for us. Along with deceptive behavior comes consequences. just because Jacob received Esau's blessings, doesn't make him any less guilty of not doing unto others as you would others to do unto you. God will repay all men accordingly.