Q: Why do Catholics make the “Sign of the Cross” after they pray?
A: Because Jesus died on the cross for the salvation of mankind. Apart from this obvious answer, it should be noted that many Christians end prayers with “in Jesus’ name we pray”. As Christians, one essential belief is the Holy Trinity. Father, Son and Holy Spirit are distinctly seperate but one. So whether you say “in Jesus name we pray” or “in God (the Fathers) name we pray” or “in the Holy Spirits name we pray”, it’s all the same. People normally don’t pray this way (at this time anyway) but the point is that it is scripturally ok. What Catholics do is simply affirm their belief in the Trinity and end the prayer with…”In the name of the Father, the Son and the Holy Spirit” and Catholics do make the sign of the Cross acknowledging the death and sacrifice of our Lord. We always want to keep the cross in the forefront. We never want to forget that sacrifice and why we should sin no more. Only the enemy would want us not to keep the Cross of Calvary on our minds, in our hearts, on our churches, around our necks.. etc. We love the cross because without it, there would be no resurrection.
Even Martin Luther urged his followers to use the sign. In his Catechism of 1529 he instructed fathers to teach their households the following: “In the morning, when you rise from bed, sign yourself with the holy cross and say, ‘In the name of the Father, the Son, and the Holy Spirit. Amen.’…At night, when you go to bed, sign yourself with the holy cross and say, ‘In the name of the Father, the Son, and the Holy Spirit. Amen.'”*1
1. www.catholic.com Catholic Customs article The Sign of the Cross
“Always be prepared to make a defense to anyone who calls you to account for the hope that is in you”
1 Peter 3:15