Christianity may be rightly understood as an Exchange Co-operative. Christ offers to bear our sins in exchange for our bearing His righteousness. We are then to turn around and offer to bear other's burdens in exchange for ours in some measure.
We are made such that our burdens are custom designed for just us and thus very hard for us to bear while the burdens of others seem light to us. Thus to exchange burdens means everyone gets a lighter load. This is the power of Christ's economy.
Love is entering into another's hopes and burdens. Marriage is, of course, intended to be a co-inherent life, representing as it does the co-inherence of Christ and the Church.
h/t Charles Williams