God knows that we cannot establish contact with him without his help. This is why Jesus instituted the sacraments. God is present in the sacraments in a very concrete way.
You can regard a sacrament as a kind of ‘gateway’ that God uses to provide us with instant access to his grace. There are seven sacraments: Baptism, Confirmation, Eucharist, Reconciliation, Anointing of the Sick, Marriage, and Ordination.