Joseph sacrificed what was he deserved for what Mary needed, and as followers of Christ we also sacrifice what we deserve, what may be rightfully and legally ours for the needs of others. (Matthew 1:18-25)
Love does not replace or override the commandments. Love is a summary of the commandments and to love others is to apply the commandments for their benefit, in the same way we apply them to ourselves. (Romans 13:9-14)