And you shall not go up by steps to My altar, so that your nakedness will not be exposed on it.' (Exodus 20:26)
The Levites were commanded not to go up by steps to G-d's altar.
Messiah implicitly affirmed this commandment when He spoke about the Law:
"Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill. For truly I say to you, until heaven and earth pass away, not the smallest letter or stroke shall pass from the Law until all is accomplished. Whoever then annuls one of the least of these commandments, and teaches others to do the same, shall be called least in the kingdom of heaven; but whoever keeps and teaches them, he shall be called great in the kingdom of heaven. (Matthew 5:17-19)
This commandment pictures Messiah and the reverent manner in which He approached G-d in prayer. Having a reverence for G-d and awe of Who He is should cause us to consider even the manner in which we approach Him.
Messiah fulfilled this commandment by not climbing steps to the altar.
Traditionally speaking, this commandment is observed by using a ramp (instead of steps) to go from the ground to the [bronze] altar. In the absence of a Temple no altar exists and so no ramp is needed at this time.
This commandment is dependent upon a Temple/Tabernacle being in place. We are unable to literally fulfill this commandment today.