Are the Sacraments a Sign of God's Mercy?

The whole point behind god giving us his grace through the sacraments is to serve as visible signs of what he is doing. You would not know if you were validly baptized, because you would have no way of knowing whether the person who baptized you was in a state of Grace. So this would create a nightmare scenario. And god is too merciful to let that happen. Now, jonathan had a second question. Is it accurate to say that anybody baptized validly in a protestant church actually becomes catholic? No, because they are put in a relationship with the catholic church but they are not fully incorporated into it.