Jacob coveted Esau's blessing and used a masquerade to steal it. The measure Jacob measured with was measured back (Mt 7:2) to him when he woke up the morning after his wedding to find that his new bride was not his beloved Rachel, but her sister Leah, who had masqueraded as Rachel (Gn 29:25).
We humans are so prone to deception and covetousness that God felt it necessary to have the last two of the ten commandments forbid coveting someone else's spouse or goods (Ex 20:17; Dt 5:21). God knows that we tend to think "the grass is greener on the other side." We want to "keep up with the Joneses." We are dissatisfied with "ours" and want "theirs."
Before Jacob was born, the Lord promised that Jacob would be especially blessed and would surpass Esau (Gn 25:23). So why should Jacob want to covet a lesser blessing (and bear all the horrible consequences of stealing it as well)? All Jacob had to do was be himself and wait for God's blessing to come in due time.
There's a Jacob lurking in us. We envy and "cannot acquire, so [we] quarrel and fight" (Jas 4:2). Instead, the Lord commands us: "Be content with what you have" (Heb 13:5). And what is it we have? We have a place in Christ's body prepared (Jn 14:2) for us from the beginning of time (Eph 1:4-5; 2:10; Heb 11:40). We have "every spiritual blessing in the heavens!" (Eph 1:3)
Why settle for less? Live the life God has assigned to you (1 Cor 7:17). Be all that you can be — in Jesus.